FLORA OF SOUTHERN AFRICA

HEPATOPHYTA

Editor OA. Leistner

Parti: Marchantiopsida

Fascicle 1: Marchantiidae

by Sarie M. Perold

O T A N I C A L

Digitized by the Internet Archive

in 2016

https://archive.org/details/floraofsoutherna11unse_0

FLORA OF SOUTHERN AFRICA

which deals with the territories of

SOUTH AFRICA, LESOTHO, SWAZILAND, NAMIBIA AND BOTSWANA

HEPATOPHYTA

PARTI: MARCHANTIOPSIDA

Fascicle 1: Marchantiidae

by

Sarie M. Perold

with drawings by

G. Condy, J. Kimpton, A. Pienaar & M. Steyn

Scientific editor: O.A. Leistner

Technical editor: B.A. Momberg

NATIONAL

Botanical

INSTITUTE

Pretoria

1999

Editorial Board

B.J. Huntley

R.B. Nordenstam

W. Greuter

National Botanical Institute, Cape Town, RSA

Natural History Museum, Stockholm, Sweden

Botanischer Garten und Botanisches Museum,

Berlin-Dahlem, Berlin, Germany

Typesetting and page layout by S.S. Brink, NBI, Pretoria

Reproduction by Afriscot Litho (Pty) Ltd, P.O. Box 23663, Innesdale, 0031 Pretoria

Printed by Execuprint, P.O. Box 316, Wierda Park, 0149 Pretoria

© published by and obtainable from the

National Botanical Institute, Private Bag X 1 0 1 , Pretoria, 0001 South Africa

Tel. (012) 804-3200 Fax (012) 804-3211

ISBN 1-919795-44-8

CONTENTS

Introduction 1

Vegetation formations in the FSA area 1

Collecting and preservation 3

Study and identification 3

Characters used in keys and descriptions 4

Descriptions and illustrations 5

Classification 6

Glossary 8

Subclass Marchantiidae R.M.Schust. 11

Order Marchantiales Limpr. 11

Key to local suborders of Marchantiales 12

Key to local genera of Marchantiales 13

Suborder Targioniineae R.M.Schust. 14

Family Targioniacea e Dumort. 15

Subfamily Targionioideae Grolle 15

Targionia (P.Micheli) L 15

T. hypophylla L 17

Suborder Marchantiineae Limpr. 18

Key to local families of Marchantiineae 20

Family Lunulariaceae H.Klinggr. 21

Lunularia Adans 21

L. cruciata (L.) Dumort. ex Lindb 21

Family Aytoniaceae Cavers 25

Subfamily Aytonioideae 26

Key to local genera and two species of Aytoniaceae 26

Plagiochasma Lehm. & Lindenb 27

Key to subgenera and species of Plagiochasma 27

Subgenus Micropylum Bischl 28

1. P. rupestre (J.R.Forst. & G.Forst.) Steph 28

la. var. rupestre 29

lb. var. volkii Bischl 31

Subgenus Plagiochasma 33

2. P. appendiculatum Lehm. & Lindenb 33

3. P. microcephalum (Steph.) Steph. var. microcephalum 35

4. P. eximium (Schiffn.) Steph 37

5. P heccarianum Steph 39

Subfamily Reboulioideae Grolle 43

Asterella P.Beauv 43

Key to southern African species of Asterella 45

1 . Asterella abyssinica (Gottsche) Grolle 45

2. A. muscicola (Steph.) S.W.Arnell 48

3. A. bachmannii (Steph.) S.W.Arnell 49

4. A. marginata (Nees) S.W.Arnell 53

5. A. wilmsii (Steph.) S.W.Arnell 57

Cryptomitrium Austin ex Underw 59

C. oreades Perold 61

(iii)

Mannia Opiz 64

M. capensis (Steph.) S.W.Arnell 65

Family Cleveaceae Cavers 67

Athalamia Falc 69

A. spathysii (Lindenb.) S.Hatt 71

Family Exormothecaceae Miill.Frib 72

Exormotheca (Godm.) Mitt 73

Key to sections and species of Exormotheca in southern Africa 75

Section Exormotheca 75

1 . E. pustulosa Mitt 75

Section Corbierella (Douin & Trab.) Schiffn 78

2. E. holstii Steph 78

Family Marchantiaceae (Bisch.) Lindl 79

Key to local subfamilies of Marchantiaceae 81

Subfamily Marchantioideae (excluding Preissia) 82

Marchantia L 82

Key to local subgenera, sections and species of Marchantia 82

Subgenus Marchantia 84

1 . M. polymorpha L 84

2. M. berteroana Lehm. & Lindenb 87

Subgenus Chlamidium (Corda) Bischl 92

Section Paleaceae Bischl 92

3. M. paleacea Bertol 93

Section Chlamidium (Corda) Nees 95

4. M. pappeana Lehm 96

Section Papillatae Bischl 99

5. M. debilis K.I.Goebel 100

Subfamily Dumortieroideae R.M.Schust 101

Dumortiera Nees 103

D. hirsuta (Sw.) Nees 103

Suborder Ricciineae H.Buch 107

Key to families of Ricciineae 108

Family Oxymitraceae Miill.Frib 108

Oxymitra Bisch. ex Lindenb 109

O. cristata Garside ex Perold 109

Family Ricciaceae Rchb Ill

Key to genera of Ricciaceae 112

Ricciocarpos Corda 112

R. natans (L.) Corda 113

Riccia L 115

Key to subgenera, sections, groups and species of Riccia 116

A. Subgenus Ricciella (A. Braun) Rchb 122

A1 . Section Spongodes Nees 122

Al l Group Crystallina 123

1 . R. crystallina L. emend. Raddi 123

2. R cavernosa Hoffm. emend. Raddi 125

3. R. moenkemeyeri Steph 126

4. R cupulifera A.V.Duthie 129

A 1 .2. Group Vesiculosa 132

(iv)

5. R. bullosa Link ex Lindenb 132

6. R. garsidei Sim 134

7. R. volkii S.W.Arnell 137

8. R. rubricollis Garside & A.V.Duthie ex Perold 138

A2. Section Ricciella (A. Braun, pro gen.) Bisch 140

9. R. stricta (Lindenb.) Perold 140

10. R. purpurascens Lehm 143

B. Subgenus Thallocarpus (Lindb.) Jovet-Ast 145

11. /?. curtisii (James ex Austin) Austin 145

12. R. perssonii S. A. Kahn 147

C. Subgenus Pannosae (Perold) Perold 149

13. R. tomentosa O.H.Volk & Perold 150

D. Subgenus Chartacea Perold 152

14. R. schelpei O.H.Volk & Perold 152

E. Subgenus Riccia L 154

EL Section Riccia 154

ELI. Group Ciliatae 154

15. R. trichocarpa M.Howe 155

16. R. crozalsii Levier 155

17. R. microciliata O.H.Volk & Perold 160

18. R. natalensis Sim 161

E 1.2. Group Mammillatae 166

19. R. mammifera O.H.Volk & Perold 166

E 1.3. Group Squamatae 167

20. R. sorocarpa Bisch 167

2 1 . R. atropurpurea Sim 169

22. R. okahandjana S.W.Arnell 173

23. R. congoana Steph 175

24. R. limbata Bisch 177

25. R. angolensis Steph 179

26. R. nigrella DC 181

27 . R. macrocarpa Levier 185

28. R. pottsiana Sim 186

29. R. runssorensis Steph 191

30. R. rosea O.H.Volk & Perold 191

31. R. albolimbata S.W.Arnell 193

32. R. argenteolimbata O.H.Volk & Perold 195

33. R. albornata O.H.Volk & Perold 197

34. R. montana Perold 199

35. R. alboporosa Perold 203

36. R. bicolorata Perold 205

E2. Section Pilifer O.H.Volk 207

37. R. pulveracea Perold 207

38. R. furfuracea Perold 210

39. R. elongata Perold 212

40. R. trachyglossum Perold 213

41. /?. alatospora O.H.Volk & Perold 215

42. R. hantamensis Perold 217

43. R. parvo-areolata O.H.Volk & Perold 221

(V)

44. R. albovestita O.H.Volk 222

45. R. ampullacea Perold 223

46. R. concava Bisch 226

47. R. albomarginata Bisch 228

48. R. namaquensis Perold 230

49. R. vitrea Perold 231

50. R. villosa Steph 234

51. R. hirsuta O.H.Volk & Perold 235

52. R. simii Perold 237

Insufficiently known species 240

References 240

Index 249

Appendix A-l

Plan of the Flora of southern Africa A-l

FSA contributions in Bothalia A-3

Flora of southern Africa : alphabetical list of published taxa A-4

(vi)

HEPATOPHYTA: Introduction

i

INTRODUCTION

In contrast to the volume of work published on southern African mosses, the liverworts have

been a rather neglected group. Bischoff ( 1 846), Gottsche, Lindenberg & Nees ( 1 844-1847) as well

as Stephani (1886a, b, 1891, 1892, 1894, 1895a, b, 1898, 1899, 1901a, b, 1905, 1912, 1913) de-

scribed a number of our liverworts, and during the present century Sim (1915, 1926, 1932), Duthie

& Garside (1937, 1939) and S.W.Arnell (1952, 1953a, b, 1956b, 1957, 1963a, b) continued with

the work. More recent studies on thallose liverworts are by Volk (1979, 1983), Volk & Perold

(1984-1986, 1990), Perold & Volk (1988a, b), and by Perold (1986, 1989-1995), but much more

work still needs to be done on the leafy liverworts of this region.

Vegetation formations in the FSA area

The thallose liverworts treated in this fascicle are found within six of the seven biomes as

defined by Rutherford & Westfall (1986). The biomes are as follows: Desert, Savanna, Grassland,

Nama-Karoo, Succulent Karoo, Fynbos and Forest. Some liverwort species are more or less

restricted to only one of the biomes, but most exhibit a broader environmental tolerance and occur

in two or more biomes. Only one species, Riccia cavernosa, occurs in all the biomes except the

Desert Biome.

Desert Biome

This biome corresponds to the Namib Desert which forms a broad coastal belt north of the

Ltideritz area in Namibia. The arid climate and sandy substrates are not suited to the requirements

of the Hepatophyta, and there are no records of them growing in this area.

Savanna Biome

The Savanna Biome is the largest and extends into Namibia, Botswana, Northern Cape, North-

West and Northern Province, central and eastern Swaziland, lower-lying areas of KwaZulu-Natal

and Eastern Cape. Most of this biome occurs in the summer rainfall areas. The vegetation is

described as a herbaceous, usually graminoid layer with an upper layer of woody plants. With

increased canopy cover savanna is often referred to as woodland (Magill 1981). Almost all the

major stratigraphic units of southern Africa occur in this biome. The rare Riccia perssonii occurs

only in the far north of Namibia. Other species that are restricted to the Savanna Biome are Riccia

congoana, Athalamia spathysii, Plagiochasma appendiculatum, P. beccarianum and Marchantia

paleacea. Many of the other species that occur here, are also found in the Grassland Biome (see

below). Marchantia berteroana is found here as well as in the Fynbos.

Grassland Biome

The Grassland Biome is found mainly on the high central plateau of South Africa, inland areas of

the seaboard of KwaZulu-Natal and the mountainous areas of Eastern Cape. The name of this biome

is self-explanatory. Here, Riccia species often grow around flat rock outcrops. Riccia elongata is a

rare species and its distribution is restricted to a few localities in the northeastern part of this biome.

Species that occur in both the Grassland and Savanna Biomes are the following: Riccia argenteolim-

bata, R. atropurpurea, R. macrocarpa (rare), R. mammifera, R. microciliata, R. natalensis, R. volkii,

Asterella muscicola, A. wilmsii, A. bachmannii, Exormotheca holstii, Marchantia debilis, Oxymitra

cristata, Plagiochasma microcephalum var. microcephalum and P. rupestre var. volkii.

2

HEPATOPHYTA: INTRODUCTION

Nama-Karoo Biome

This biome occurs on the central plateau in Northern Cape, the southwestern Free State and the

southern interior of Namibia. Smaller areas are found in the Eastern Cape interior, Lesotho and the

interior margin of the central Namib Desert. The most common soil group in the Nama-Karoo

Biome is lime-rich. The vegetation is described as a grassy, dwarf shrubland. Except for some

species in Lesotho, none of the other liverwort species that are treated in this fascicle are restrict-

ed to this biome. Riccia bicolorata and R. namaquensis occur here as well as in the Succulent

Karoo. Others are found in the Nama-Karoo, Succulent Karoo and the Fynbos Biomes, for exam-

ple Riccia albornata, R. villosa and Asterella marginata. Riccia angolensis, R. pottsiana and R.

pulveracea occur in Grassland as well as in Nama-Karoo, whereas R. albolimbata, R. albovestita,

R. okahandjana, R. runssorensis and R. trichocarpa grow in the Grassland, Savanna and Nama-

Karoo Biomes. Those liverworts that are even more widespread, occurring in Grassland, Savanna,

Nama-Karoo and Succulent Karoo include Exormotheca pustulosa, Mannia capensis and

Plagiochasma rupestre var. rupestre.

The following species are restricted to the Nama-Karoo Biome of Lesotho [or the Afromontane

archipelago-like region of White (1983)], Riccia trachyglossum, R. montana and Cryptomitrium

oreades. Riccia ampullacea and Plagiochasma eximium also occur in the Grassland Biome, where-

as Riccia bullosa and R. sorocarpa, occur here and in the Fynbos.

Succulent Karoo Biome

The Succulent Karoo Biome is found mostly west of the western escarpment from the Liideritz

District of Namibia through the western belt of Northern and Western Cape. This is a winter rain-

fall area and the most common soil group is lime-rich as in the Nama-Karoo Biome. A number of

Riccia species are restricted to this biome, namely R. alboporosa, R. furfuracea, R. hantamensis,

R. hirsuta, R. schelpei, R. tomentosa and R. vitrea. Other species that occur here, as well as in the

Fynbos Biome, are Riccia albomarginata, R. concava and R. limbata. Riccia bicolorata and R.

namaquensis occur in this biome and also in the Nama-Karoo. Riccia albornata, R. villosa and

Asterella marginata are found here, in the Nama-Karoo and the Fynbos Biomes. Exormotheca pus-

tulosa, Mannia capensis and Plagiochasma rupestre var. rupestre are found in the Succulent

Karoo, Nama-Karoo, Grassland and Savanna Biomes.

Fynbos Biome

This biome occurs in the Western Cape and southern part of Eastern Cape. The topography is

dominated by the Cape Folded Mountain Belt. Between the coast and the mountains, the low-

lands also form part ol this biome. It is a winter rainfall area and the vegetation formation con-

tains a unique flora of ericoid and restioid elements. A few Riccia species are restricted to this

biome, namely R. alatospora, R. crozalsii, R. curtisii, R. garsidei, R. parvoareolata and R. pur-

purascens. Other species such as R. albomarginata, R. concava and R. limbata occur here as well

as in the Succulent Karoo. Riccia bullosa is found in the Fynbos, Succulent Karoo and the Nama-

Karoo of Lesotho. Riccia stricta, Dumortiera hirsuta, Lunularia cruciata and Marchantia pap-

peana var. pappeana occur in the Fynbos, Savanna and Grassland Biomes. Riccia cupulifera and

P nigrella range from the Fynbos to the Succulent Karoo and Grassland. Riccia simii is very

widespread and is found in the Fynbos, Nama-Karoo, Grassland and Savanna Biomes. Targionia

hypophylla is equally widespread, occurring in the Fynbos, Succulent Karoo, Grassland and

Savanna Biomes.

HEPATOPHYTA: INTRODUCTION

3

Forest Biome

This is by far the smallest biome in southern Africa and the only forest area of biome dimension

occurs in the southern Western Cape. The very rare Riccia rubricollis is restricted to this biome.

Other liverworts that also occur here are Riccia crystallina, R. cupulifera, R. purpurascens, R. lim-

bata, Dumortiera hirsuta and Marchantia berteroana.

Collecting and preservation

It is often best to collect liverworts after rain, in other words during the rainy season, which will

be in summer for most of the country and in winter for the western Cape areas. When dry, many

thallose liverworts have their margins curved inwards, so that the dorsal face is covered. In this

‘folded’ state, they may be difficult to find.

The routine procedure for collecting liverworts is the same as that for moss specimens, except

that the samples, when removed from the substrate with a small knife, are wrapped in strips of

newspaper for protection. They are then placed into small paper bags and later allowed to air-dry

(on the same day if possible), so as to prevent fungal growth. After identification, the specimens

are rewrapped in good quality, soft absorbent paper before being stored in the same standard pack-

ets, folded from A4 paper, as those used for mosses, and described in the Introduction to Part 1,

Fascicle 1 (Magill 1981). No other preparation is necessary; washing and pressing, or the use of

glue to mount specimens on cardboard or preservation in spirit should be avoided (Jovet-Ast 1985).

Study and identification

A dissecting and a compound microscope, as well as the standard materials for preparing micro-

scope slides, are needed for the identification of liverworts. Two pairs of fine-tipped forceps and

two fine needle probes are used for the dissection of specimens; a thin razor blade is required to

make cross and sometimes horizontal sections of the thallus branches as well as sexual and sporo-

phyte structures.

Prior to dissection, some material from a specimen is removed to a microscope slide and moist-

ened with a few drops of water (at room temperature) delivered by squirting from a Pasteur pipette.

Dried thallose liverworts do not, however, always recover well when remoistened for examination.

It is therefore preferable to examine fresh material whenever possible. The fresh or dried material

(which has been allowed to revive as much as possible), is examined and observations concerning

the habit, colour and consistency of the thallus, its shape, dorsal groove (if present) and margins as

well as the presence or absence of scales, their number, colour and appendage(s) (if present), are

noted. Some terminal branches are then cleaned of all soil particles by adding more water and by

carefully and progressively removing the sand and debris with forceps. The presence of stolons, bul-

bils or gemmae (and the structure of gemma cups) should also be noted. The following should be

examined, if available, after the material has been transferred to a drop of water on a clean slide, and

a coverslip has been applied: cross sections of the cleaned branch cut by hand at mid-length or seri-

ally (for Riccia spp.) at intervals from the apex to the base; horizontal sections taken just below the

dorsal covering as well as lower down through the assimilation tissue (if the tissues remain a little

shrunken in the sections, they can be stretched lightly with the fine probes); some carefully detached

ventral scales; sections of androecia and, if gametangiophores are present, cross sections of the stalk,

and scales from its base, along its length and apex (if present); from the rarely raised male recepta-

cle, the margin of the rays and ventral median scales; and from the carpocephalum, parts of the cap-

sule wall, involucres and, if present, the pseudoperianth. As the water evaporates during examina-

tion under the compound microscope, more can be added. For taking measurements and for pho-

4

HEPATOPHYTA: INTRODUCTION

tography, water-mounted material is routinely used. To make more durable preparations, the sections

and scales can be mounted in Hoyer’s medium (Magill 1981: xiii); it, however, causes shrinkage and

severe bleaching of the delicate tissues.

Characters used in keys and descriptions

Thallus. Characters describing the size, growth form, habit and colour are obtained from the

specimens examined, but are frequently somewhat subjective. The nature of the margins, inflexed

or not, is sometimes important in identification and should be observed in both wet and dry condi-

tion. The forking of the branches, whether shortly or deeply divided, the degree of divergence and

the shape, which refers to that of the terminal segment, are also noted from the specimens. The size

categories of the thallus branches referred to in the descriptions, more or less correspond to the fol-

lowing list, but are sometimes rather arbitrary and not universally applicable. Where taxa span

more than one category, deviations are bound to occur. The length of the branches is measured from

the apex to the base, and the width is taken across the widest part of the terminal segment.

Branch size categories. Very small to small: 1. 0-4.0 (-5.0) x 0.6-1. 5(-2.0) mm. Smallish to

medium-sized: 5.0-10.0 x (0.6— )0. 8-2.0 mm. Medium-sized: 5.0-10.0(-12.0) x ( 1 .0— )3. 0-4.0 mm.

Large: up to 15.0 x 2.0-5. 5 mm. Very large: more than 18.0 x 4.0-6.0(-8.0) mm. The thickness of

the branches is measured medianly on cross sections; the ratio of the width to thickness is based on

measurements taken in the same way. The slope of the flanks can also be observed in cross sections.

Scales. The presence (or absence), number of rows, and sometimes the fraction of the ventral

face of the thallus covered by them, as well as the colour, size, shape, position, margins and

appendages of the scales are often important taxonomic characters and are frequently used in the

keys to identify species.

Cilia. A few species of Riccia have ciliate margins, and microscopic examination and measure-

ment of the cilia should help to distinguish between them.

Dorsal epidermis (or epithelium). Under the dissecting microscope it can be observed whether

the dorsal cells of the thallus are chlorophyllose or echlorophyllose and interrupted by defined

pores, or form an even, ± homogeneous upper surface of echlorophyllose cells in one or two

storeys, or whether they form free-standing, multicellular pillars. Subdorsal horizontal and cross

sections are always taken to measure the cells and to note their shape as well as the occasional pres-

ence of trigones. In Riccia section Pilifer the cells of the dorsal pillars, as cited in the keys and

descriptions, are used in conjunction with other characters, to distinguish between the different

species. The first figure of the cell measurements refers to the long axis and the second to the width.

Air pores. The following should be noted: whether simple or compound (in Marchantia spp.),

slightly or much raised, number of surrounding cell rings and the thickness of radial walls by using

horizontal and cross sections. Only in Marchantia are air pores also viewed from below.

Assimilation tissue. Cross and horizontal sections reveal whether the assimilation tissue is

spongy and a honeycomb of rather irregular walls and wide air chambers, the latter sometimes

empty or filled with chlorophyllose filaments, or whether the cells in the assimilation tissue layer

are closely packed together and only separated by narrow vertical air canals.

Male and female receptacles. Their position, size, shape, accompanying structures and mem-

branes are studied. In Riccia species it should be noted whether the internally borne sporangia

bulge dorsally or ventrally or whether they are deeply embedded.

HEPATOPHYTA: Introduction

5

Spores and elaters (when the latter are present). Mature, well-formed spores (and elaters) are

mounted on microscope slides in Hoyer’s medium to measure their size and other features. The

shape and colour should also be observed, as well as details of the ornamentation. For SEM exam-

ination, spores from the same sample are mounted on aluminium stubs with double-sided tape and

gold-coated. Spore characters are very important in distinguishing between species, particularly in

Riccia, and many can easily be recognized solely by their ornamentation.

Descriptions and illustrations

Authors of plant names are abbreviated according to Brummitt & Powell (1992), with the

exception of Jovet-Ast.

Descriptions of eight families, 13 genera and 75 species of the locally occurring Marchantiales

are given. Only the genus Riccia has many species in southern Africa, whereas seven of the gen-

era included here are represented by only one local species or are monotypic.

Illustrations were prepared by Mesdames Gillian Condy, Jill Kimpton (who did all but one of

the Ricciaceae), Anne Pienaar and Marietjie Steyn. The habit drawings were done by direct obser-

vation of selected wet and sometimes dry plants as well, using a dissecting microscope. All other

parts were drawn from photographs, taken by the author, using a photographic apparatus attached

to a compound microscope.

6

HEPATOPHYTA: CLASSIFICATION

CLASSIFICATION

Stotler & Crandall-Stotler (1977) and Bartholomew-Began (1990) are followed in considering

the liverworts a separate division, the Hepatophyta (or Hepaticophyta), and not a class of the divi-

sion Bryophyta (Schuster 1984b). The hornworts are also placed in a separate division, the

Anthocerotophyta.

Schuster (1992b) includes the order Sphaerocarpales (and the extra-southern African

Monocleales), together with the order Marchantiales, in the subclass Marchantiidae.

Here, only the order Marchantiales has been referred to the subclass Marchantiidae, which is

dealt with in fascicle 1 of part 1: class Marchantiopsida. The order Sphaerocarpales (subclass

Sphaerocarpidae) has not recently been studied in southern Africa as very little new material has

been collected since the last treatments of its constituent genera, namely Riella by Wigglesworth

(1937), Riella and Sphaerocarpos by Proskauer (1955) and Monocarpus by Schelpe (1969). Only

if new collections come to hand, can these genera be revised meaningfully.

Schuster (1992c) is followed in recognizing the suborder Targioniineae, and the subfamily

Dumortieroideae. The classification of the Aytoniaceae is after Grolle (1983a, b), and of the

Ricciaceae partly after Grolle (1983a, b), and also partly after Jovet-Ast (1975), with the elevation

of Thallocarpus to the status of subgenus. Schuster’s rather controversial treatment of the Ricciaceae

(Schuster 1992c), with the institution of many new sections, has not been followed here. Two other

subgenera, unique to southern Africa, have been instituted: Chartacea and Pannosae. Section Pilifer

(Volk 1983) is placed under subgenus Riccia, and not under subgenus Pteroriccia (Schuster 1985).

Na-Thalang’s (1980) example was partly followed in dividing section Riccia into the groups:

Ciliatae, Mammillatae and Squamatae; section Spongodes was divided into two groups: Crystallina

and Vesiculosa. The other two recently recognized subgenera, Viridisquamata and Leptoriccia, do

not occur in southern Africa.

Extra-southern African families have generally not been included.

DIVISION BRYOPHYTA (mosses) (Magill 1981, 1987; Magill & Van Rooy 1998)

DIVISION HEPATOPHYTA (liverworts)

Part 1. Class Marchantiopsida Stotler & Stotl.-Crand. (1977)

Fascicle 1. Subclass Marchantiidae R.M.Schust. (1953)

Order Marchantiales Limpr. (1876)

Suborder Targioniineae R.M.Schust. (1958)

Family Targioniaceae Dumort. (1829)

Subfamily Targionioideae Schiff. (1893)

Cyathodioideae Grolle (1992)

Suborder Marchantiineae Limpr. (1876)

Family Lunulariaceae H.Klinggr. (1858)

Aytoniaceae Cavers (1911)

Subfamily Aytonioideae

Reboulioideae Grolle (1976)

Family Cleveaceae Cavers (1911)

Exormothecaceae Miill.Frib. in Grolle (1972)

Marchantiaceae (Bisch.) Lindl. (1836)

Subfamily Marchantioideae

Dumortieroideae R.M.Schust. (1984a)

HEPATOPHYTA: CLASSIFICATION

7

Suborder Ricciineae H.Buch. (1936)

Family Oxymitraceae Miill.Frib. (1940)

Ricciaceae Rchb. (1828)

Fascicle 2. Subclass Sphaerocarpidae

Order Sphaerocarpales

Suborder Sphaerocarpineae

Family Sphaerocarpaceae

Suborder Riellineae

Family Riellaceae

Suborder Monocarpineae

Family Monocarpaceae

Part 2. Class Jungermanniopsida Stotler & Stotl.-Crand. (1977)

Fascicle 1. Subclass Metzgeriidae

Order Haplomitriales

Family Haplomitriaceae

Order Metzgeriales

Family Fossombroniaceae

Pallaviciniaceae

Aneuraceae

Metzgeriaceae

Fascicle 2. Subclass Jungermanniidae (Schuster 1953 as Jungermanniae)

Order Jungermanniales

Family Lepicoleaceae

Herbertaceae

Lepidoziaceae

Calypogeiaceae

Adelanthaceae

Cephaloziaceae

Cephaloziellaceae

Antheliaceae

Jungermanniaceae

Gymnomitraceae

Scapaniaceae

Geocalycaceae

Plagiochilaceae

Arnelliaceae

Acrobolbaceae

Schistochilaceae

Balantiopsidaceae

Pleuroziaceae

Radulaceae

Ptilidiaceae

Porellaceae

Jubulaceae (inch Frullaniaceae)

Lejeuneaceae

DIVISION ANTHOCEROTOPHYTA (hornworts)

Class Anthocerotopsida

Order Anthocerotales

Family Anthocerotaceae

HEPATOPHYTA: Glossary

GLOSSARY

The terms used have for the most part been dealt with in the Glossary of Bryophyta (Magill

1981: 1-12). A few of the more commonly used ones are repeated here plus some which pertain

only to liverworts.

acropetal — referring to organs developing from

the base toward the apex,

air pores — minute, regular spaces or simple or

compound, delimited stomata in dorsal cover-

ing of thallus, functioning in gas exchange,

air canals— narrow vertical interstices separat-

ing columns of chlorophyllose cells in the as-

similation tissue.

air chambers — wide polyhedral air cavities,

mostly enclosed by unistratose echlorophyllose

or chlorophyllose cell plates in the assimilation

tissue.

alveolus (pi. alveoli)— small angular or polygo-

nal areas bordered by ridges and forming a

pattern or network; applied to ornamentation

in many spores; some workers, however, pre-

fer to use the term ‘areola’,

anastomose — interconnecting; applied to orna-

mentation in some spores,

androecium (pi. androecia) — antheridia group-

ed together.

anisopolar — proximal and distal spore faces

differently ornamented.

annular thickenings — ring-like thickenings

extending over both tangential and radial cell

walls in liverwort capsules,

antheridiophore — specialized antheridium-

bearing branch, the male gametangiophore,

e.g. in Marchantia.

antheridium (pi. antheridia) — male gametang-

ium, multicellular structure containing sperma-

tozoids.

apical — at the apex or terminal end of the thal-

lus branch.

apolar spores — spores with no obviously dis-

tinct polarity, lacking a conspicuous triradiate

mark (opposed to polar),

archegoniophore — a specialized archegonium-

bearing branch, the female gametangiophore,

e.g. in Marchantia.

archegonium (pi. archegonia) — female game-

tangium; multicellular, flask-shaped structure

containing ovum.

areolate — the cellular networdk of a thallus or leaf.

autoicous — with antheridia and archegonia in

separate clusters on the same plant.

basal — at the base or proximal end of the thal-

lus branch.

bifurcate — divided or forked into two basically

equal parts.

bulbil — vegetative propagule; a small, bulb-like

bud.

calyptra — membranous covering of haploid tis-

sue over developing sporophyte, derived from

archegonial venter, ruptures near the apex and

remains at base of seta.

carpocephalum — specialized, often radially sym-

metrical receptacle bearing sporangia, held

aloft by a stalk.

cavernous — with numerous cavities in the tissue.

chlorophyllose — containing chlorophyll; green,

as opposed to hyaline.

cilium (pi. cilia) — hair-like appendages along

cupule margins or involucre margins in some

Marchantia species or along thallus margins

in some Riccia species.

cleistocarpous — referring to indehiscent capsules

lacking valves and hence opening irregularly.

crenate — with rounded teeth; applied to scale

margins.

crenulate — with minute, rounded teeth; applied

to the spore wing in some species.

cupule — see gemma cupule.

dentate — with sharp teeth; applied to the scale

margins in a few species.

dioicous — with archegonia and antheridia on

separate plants.

distal — the outer, convex face of a spore, away

from the sides of contact (opposed to proximal).

HEPATOPHYTA: GLOSSARY

9

divergent — turned in different directions,

dorsal — the upper surface of the thallus, away

from the substrate.

elater (pi. elaters) — a differentiated, elongate

cell usually with helical wall thickenings, in

most liverwort capsules admixed with spores,

emarginate — having a marginal indentation or

notch at the thallus apex,

epidermis — the outer cell layer of the thallus in

those species with defined stomata, sometimes

becoming cavernous.

epithelium — the outer cell layer(s) of the thal-

lus in those species of Riccia with minute

spaces for air pores.

erose — irregularly and finely notched; applied

to the spore wing in some species,

filiform — filamentous, threadlike,

flanks — sides of thallus.

foveolate — pitted; applied to the spore orna-

mentation in some species,

gametangium (pi. gametangia) — i.e. archegonium,

antheridium which is vessel(s) bearing gametes,

gamete — male or female reproductive cell,

gametoecium — gametangia and surrounding bracts,

gemma cupule — cup-shaped, gemmae-containing

structure of thallus origin, e.g. in Marchantia ,

Lunularia.

globose — spherical.

granular — with minute, blunt projections,

gregarious — growing together, but not closely

touching as in mats.

gynoecium (pi. gynoecia) — female inflorescence

often consisting of archegonia, surrounding ca-

lyptra and involucre.

habit — the aspect or general appearance of a

thallus.

habitat — local environment,

hyaline — clear and colourless like glass, and

transparent; applied to echlorophyllose cells of

dorsal epithelium or to scales in some species,

idioblast — a uniquely differentiated cell, dis-

tinct in size and contents from the other cells

of the same tissue.

imbricate — closely appressed and overlapping

like shingles on a roof.

incrassate — with thickened cell walls,

inflexed — bent upward and inward; applied to

thallus margins.

involucre — a protective sheath of tissue of thallus

origin surrounding archegonium or sporophyte.

mammillose — (of cells) bulging, and/or with a

hollow papilla-like protuberance,

monoicous — with antheridia and archegonia on

the same plant.

neck — the narrow elongated upper end of the

archegonium or antheridium.

oblique — slanted; applied to the slope of the

flanks of the thallus in many species,

oil cell — cell characterized by the inclusion of a

large oil body or organelle containing ter-

penes.

palea (pi. paleae) — scale(s) encircling androe-

cia and gynoecia.

palmate — lobed or divided like fingers, refer-

ring to the female receptacle in some Mar-

chantia species.

papilla (pi. papillae)— a minute protuberance

of various forms.

papillate — loosely applied to minutely rough sur-

face; bearing minute pimple-like protuberances,

paroicous — bearing the antheridia and arche-

gonia close together in a single gametoecium

but not mixed.

pedicel — stalk bearing gametangia.

polar spore — spores with a discernible to con-

spicuous triradiate mark on the proximal face,

postical — belonging to the undersurface or back.

proximal — applied to the internal face of a

spore (opposed to distal),

pseudodichotomous — referring to the forking

of the axis into two, more or less equal branch-

es of the thallus, but not by equal division of

an apical cell; false dichotomy,

pseudoperianth — tissue of thallus origin sur-

rounding the archegonial cluster, calyptra and

later the sporophyte, e.g. in Asterella and

Marchantia.

receptacle — a disc, or wart-like mass of tissue,

bearing antheridia or archegonia and found

directly on the thallus or raised on a stalk.

10

HEPATOPHYTA: Glossary

reticulate — netted, referring to the network

pattern produced by alveoli on spore faces,

rhizoid — roothair-like structures that theoreti-

cally function in absorption and anchorage,

one-celled (in liverworts) and usually hyaline,

smooth or pegged.

rhizoid furrow— a longitudinal, rhizoid-bear-

ing channel or groove on the postical surface

of a stalk.

rosette — growth habit with thalli radiating from

a central point.

scales — thin, membranous structures, in two or

more rows, on the undersides or flanks of the

thallus.

sessile— affixed directly on the thallus, without

a stalk.

seta — elongated portion of the sporophyte be-

tween capsule and foot.

sporangium — -capsule; spore-producing struc-

ture, rarely embedded in thallus tissue,

sporophyte — the spore-bearing generation,

typically consisting of foot, seta and capsule,

stalk — -cylindrical structure carrying archego-

nial and rarely antheridial receptacles,

stolon — slender, ± vertical underground stem,

storage tissue — the ventral ± '/2— V3 or more of

thallus, composed of cells sometimes inter-

spersed with oil or sclerotic cells or mucilage

cavities.

succulent — thick and fleshy,

terete — circular in cross section,

tetrad — a group of 4 developing, or rarely

mature, spores (permanently grouped so in a

few Riccia species).

tetrahedral — four-sided.

thallus — a more or less flattened vegetative body,

without differentiation into a stem and leaves.

triangular-globular — applied to a polar spore,

the inner face of which has 3 facets separated

by the arms of a triradiate mark; the outer face

is convex.

trigone — generally triangular intracellular wall

thickenings, at the point where 3 (or more)

cells meet, often in epidermis of liverworts.

triradiate mark — prominent ridges in the

shape of a ‘y’ on the proximal face of a spore.

tumid— swollen.

umbonate — convex with an abrupt, rounded

central point.

undulate — wavy.

valve — one of the parts or partially detached

flaps of tissue into which the capsule of many

liverworts separates upon dehiscence.

venter — the expanded portion of the archegoni-

um that encloses the egg.

ventral — referring to the lower surface, next to

the substrate (opposed to dorsal).

vermiculate — long, narrow, somewhat wavy,

usually with rounded ends; applied to the

ornamentation of some spores.

verruculose — irregularly roughened; applied to

the ornamentation of some spores.

wart — a small elevation or protuberance.

wing— loosely applied to the lamina of a thallus

or to the thin, flat expansion at the margin of

the spore.

HEPATOPHYTA: Marchantiidae/Marchantiales

11

SUBCLASS MARCHANTIIDAE

Marchantiidae R.M.Schust., Boreal Hepaticae, a manual of the liverworts of Minnesota and adja-

cent regions. The American Midland Naturalist 49: 257-684 (1953).

Plants thallose, generally creeping, pseudodichotomously branching, dorsiventral, with marked

tissue differentiation. Dorsal epidermis often lacking chloroplasts, interrupted by air pores (or small

openings). Assimilation tissue with air chambers (or air canals), the former sometimes containing

chlorophyliose filaments; storage tissue ventral; oil bodies large, spherical, solitary, in somewhat

smaller cells that lack chloroplasts, scattered throughout all tissues, absent in Athalamia and Riccia

species; ventral epidermis mostly bearing scales and dimorphic, smooth or pegged rhizoids.

Sexual reproduction by specialized propagules rare, very occasionally reproducing by multicel-

lular gemmae.

Antheridia usually in groups, generally ellipsoidal, on short pedicel, often aggregated in sessile,

very rarely stalked, androecial receptacles. Archegonia with neck normally formed of 6 rows of cells,

frequently aggregated in stalked gynoecial receptacles, sometimes internal, rarely ventrally displaced;

calyptra 1-4 cell layers thick, often surrounded by individual involucres. Sporophyte with capsule

wall unistratose, except occasionally for a small, bistratose, apical area, dehiscing variously or not at

all. Spores usually large, often clearly polar. Elaters mostly slender, twisted, sometimes absent.

Only the Marchantiales, with three local suborders, have been referred to the Marchantiidae in

this treatment.

ORDER MARCHANTIALES

Marchantiales Limpr. Lebermoose. In F. Cohn, Kryptogamen-Flora von Schlesien: 225 (1876);

R.M.Schust.: 1 (1992c).

Thalli small to very large, scattered or in loose or crowded patches, sometimes in rosettes; light

green, green, glaucous green or dark green, usually firm but sometimes spongy and rather delicate.

Branches simple or once to several times pseudodichotomously furcate, occasionally with ventro-

lateral or apical innovations, linear to oblong or obovate, apex entire or notched, tips of apical

scales often recurved over edge; groove occasionally present or thallus dorsally flat to slightly con-

cave, margins acute to obtuse; flanks sloping obliquely or sometimes almost vertical; ventral face

medianly keeled or rounded. Scales ventral or ventrolateral, small to large, in 2-4(6) rows, hyaline

or pigmented, variously shaped, with or without appendages, with or without oil cells.

Dorsal epidermis (or epithelium) unistratose, very occasionally partly or wholly bistratose, some-

times in free cell pillars; air pores simple, rarely much raised, occasionally only small spaces between

cells, rarely compound, very seldom dorsal epidermis and pores absent. Assimilation tissue with one

storey (or more) of partitioned air chambers, rarely subdivided, walls unistratose, cells with or with-

out many small chloroplasts, spaces empty or containing chlorophyliose filaments, sometimes with

narrow, vertical air canals enclosed by chlorophyliose cell columns; storage tissue parenchymatous;

sometimes also present, oil cells, slime cells, sclerotic cells or cells with pitted walls.

Asexual reproduction usually lacking, occasionally by means of discoid gemmae borne in dor-

sal gemma cupules or sometimes perennating by ventral bulbils, tubers or stolons.

12

HEPATOPHYTA: Marchantiales

Monoicous, autoicous, dioicous or paroicous. Antheridia sometimes in median rows dorsally

sunken into thallus or immersed in well-defined sessile cushions or discs, rarely in stalked recep-

tacles, often opening into conical protuberances. Archegonia with moderately long necks, general-

ly in stalked receptacles, sometimes sunken in thallus in dorsal median row, very occasionally in

sessile gynoecia, rarely ventrally displaced below thallus apex and enclosed in black bivalved

involucre ( Targionia ). Sporophytes with reduced foot and short seta present or absent, capsule glo-

bose, wall with or without thickenings, dehiscence various. Spores generally large, mostly polar,

often triangular-globular, rarely retained in permanent tetrads, variously ornamented. Elaters usu-

ally bi- or trispiral, rarely reduced, sometimes absent. Chromosome numbers : n = 9 or multiples

thereof, 18, 27, 36, or in Ricciineae 8, 10, 12, 15 or 24.

Members of the order have a worldwide distribution; many are pioneers of harsh biotopes, of

semi-arid and arid areas, as well as arctic-antarctic, alpine and tropical mountain regions. Some

also colonize disturbed mesic habitats and have become commensals of human activity (Bischler

1988).

The Marchantiales are said to form one of the summits of liverwort evolution (Schuster 1984b);

tissue differentiation of the gametophyte is markedly complex and sporophyte reduction has been

carried to the extreme in the Ricciaceae.

Locally, the order Marchantiales includes the following three suborders: Targioniineae,

Marchantiineae and Ricciineae. The Corsiniineae have no representatives in southern Africa nor do

the Monocleales. The subclass Sphaerocarpiidae has been excluded in this treatment for reasons

already stated.

Key to local suborders of Marchantiales

la Thalli medium-sized to robust, 2-10 mm wide, distantly or infrequently branching, some-

times with apical or ventrolateral innovations, not forming rosettes; archegonia in

receptacles mostly raised on stalks, very rarely dorsally sessile on thallus or ventrally

displaced below apex; sporophyte with distinct foot and seta; capsule wall persistent,

not disintegrating at maturity; elaters present, mostly long and thin, rarely reduced:

2a Air pores of thallus simple, surrounded by several rings of differentiated cells, epider-

mal cells with distinct trigones; gemma cups absent; sporophyte single per recepta-

cle, ventrally displaced below apex of thallus, thus inhibiting further apical growth;

capsule wall with annular thickenings; calyptra smooth, delicate; involucre conspi-

cuous, thick-walled, mussel-like, black; elaters long and thin Targioniineae (p. 14)

2b Air pores of thallus simple, slightly or rarely much raised, sometimes compound, epi-

dermal cells with or without trigones; very rarely epidermis and pores lacking;

gemma cups sometimes present; sporophytes mostly 2 to several per receptacle,

which is almost always raised on a stalk, very rarely dorsally sessile on thallus; calyp-

tra delicate but pluristratose at maturity; elaters distinct, mostly long and thin, rarely

reduced Marchantiineae (p. 18)

lb Thalli usually small to medium-sized, l^f mm wide, mostly repeatedly pseudodichoto-

mously closely furcate, frequently forming partial or complete rosettes; antheridia and

archegonia (and sporophytes) embedded in thallus, very rarely dorsally sessile on thal-

lus; sporophyte without foot and seta; capsule wall delicate, without thickenings,

resorbed at maturity; elaters absent Ricciineae (p. 107)

HEPATOPHYTA: MARCHANTIALES

13

Key to local genera of Marchantiales

la Thalli large, dark green, translucent, margins hirsute; dorsal epidermis, air pores and air

chambers absent; male and female receptacles raised on stalks but male stalks very short

Dumortiera (p. 103)

lb Thalli small to large, various shades of green, margins not hirsute; dorsal epidermis (or

epithelium), air pores (or openings), air chambers (or canals) present; gametangia

stalked, sessile or embedded:

2a Thalli smallish to large, not in rosettes, dorsal groove absent; female receptacles raised

on stalks, very rarely sessile; capsule dehiscence by lid or valves; elaters present:

3a Air chambers containing short, erect, chlorophyllose filaments or subdivided by sec-

ondary walls or plates:

4a Air chambers much elevated Exormotheca (p. 73)

4b Air chambers not elevated:

5a Air pores of thallus compound, barrel-shaped (formed by 3-5 superimposed con-

centric rings of cells); round gemma cups present; male and female receptacles

raised on longish stalks Marchantia (p. 82)

5b Air pores of thallus simple, surrounded by 1-3 concentric rings of cells, with or

without collapsed inner cell ring; rarely with crescentic gemma cups; female

receptacle almost invariably raised on stalk:

6a Thalli dark green or bright green, margins purple; dorsal epidermal cells with dis-

tinct trigones; ventral scales dark purple, obliquely triangular, appendage(s)

tapering, basally not constricted; gemma cups absent:

7a Air pores large, white-encircled; gynoecia ventrally displaced below thallus apex,

sessile; involucre mussel-shaped, black, leathery Targionia (p. 15)

7b Air pores less obvious, smaller; female receptacle raised on stalk; involucre bell-

shaped, membranous Mannia (p. 64)

6b Thalli bright yellow-green, margins hyaline; dorsal epidermal cells thin- or thick-

walled, trigones lacking; ventral scales ± hyaline, appendage rounded, basally

deeply constricted; crescentic gemma cups present Lunularia (p. 21)

3b Air chambers empty, in one to several storeys, bounding walls chlorophyllose:

8a Female receptacle on stalk arising dorsally on thallus, away from apex; stalk lacking

rhizoid furrow:

9a Thalli and ventral scales with scattered oil cells; rarely air pores tiny, stellate,

appearing plugged; antheridia in sessile, cushion-like receptacles

Plagiochasma (p. 27)

9b Thalli and ventral scales lacking oil cells; radial walls of single ring of cells sur-

rounding stellate air pores thickened, not appearing plugged; antheridia scattered

medianly, sunken Athalamia (p. 69)

8b Female receptacle on stalk arising from apical notch of thallus or at side of thallus;

stalk with 1 rhizoid furrow:

10a Female receptacle round or umbonate, on stalk arising from apical notch of thal-

lus; pseudoperianth present, basket-like; ventral scales of thallus with lanceolate

or ovate appendages Asterella (p. 43)

10b Female receptacle disciform-round, on stalk arising ventrolaterally and emerging

at side of thallus; pseudoperianth absent; ventral scales of thallus with filiform

appendages Cryptomitrium (p. 59)

14

HEPATOPHYTA: Marchantiales/Targioniineae

2b Thalli small to medium-sized, frequently in complete or partial rosettes; dorsal groove

often present; sporangia very rarely sessile, otherwise always embedded in thallus;

capsule cleistocarpous; elaters absent:

1 1 a Air pores stellate, with thickened radial walls; oil cells absent; sporangia dorsally ses-

sile on thallus, enclosed above by continuous crest-like involucre .... Oxymitra (p. 109)

1 1 b Air pores not stellate, surrounded by undifferentiated cells or mere openings in epithe-

lium; oil cells present or absent; sporangia embedded in thallus:

12a Thalli floating or terricolous; air chambers in several storeys; scales ventral, in long

pendant purple ribbons, margins dentate, small in landform; oil cells present ....

Ricciocarpos (p. 112)

12b Thalli terricolous, very rarely floating; air chambers mostly in single storey or in

narrow canals; scales small to large, mostly rounded, very rarely triangular, mar-

gins smooth, rarely denticulate; oil cells absent Riccia (p. 1 15)

SUBORDER TARGIONIINEAE

Targioniineae R.M.Schust. in Bryologist 61: 33 (1958); R.M.Schust.: 1058-1060 (1984b); R.M.

Schust.: 61 (1992c).

[excluding Cyathodium (Perold 1993c)]

Thalli medium-sized, in crowded patches, not in rosettes; dark green. Branches simple or

repeatedly furcate, sometimes with ventrolateral innovations, linear to ligulate or obcordate, apex

entire; groove absent, thallus dorsally flat, margins acute; flanks sloping obliquely; ventral face

keeled. Scales ventral in 2 rows, one on either side of keel, large, deep purple, oil cells few.

Dorsal epidermis hyaline and firm, cells with distinct trigones; air pores conspicuous, sur-

rounded by 3 concentric rings of differentiated cells. Assimilation tissue a low storey of air cham-

bers, with chlorophyllose filaments; storage tissue parenchymatous.

Asexual reproduction absent.

Autoicous or dioicous. Androecia forming well- or poorly-defined groups at apex of reduced,

basally stipitate, ventrolateral branches, antheridia embedded, each with a conical protuberance.

Gynoecial receptacles displaced below ± entire apex of thallus. Involucres large, mussel-like,

bivalved, thick-walled and black, opening along lips of valves. Sporophyte single in each involu-

cre, subsessile, with short seta, foot distinct, capsule globose, wall with thickening bands, dehisc-

ing by irregular breaking up of upper part. Spores alveolate with larger network of raised ridges

enclosing polygonal areas, all covered by fine reticulum. Elaters up to ± 300 pm long, 12.5-18.0

pm wide, bi- or trispiral. Chromosome number, n = 9, 27.

The Targioniineae are divided into two families, Targioniaceae and Cyathodiaceae, by Hassel de

Menendez (1963) and Schuster (1992a), whereas Grolle (1972) treats these two taxa as subfami-

lies, Targionioideae and Cyathodioideae, in the single family Targioniaceae but concedes that ‘die

Verwandtschaft von Targionia und Cyathodium ist zwar locker’. Schuster (1992c) also regards

allinities between the two taxa as ‘probably rather remote’. Arnell (1963a) assigned the two gen-

era Targionia and Cyathodium to the Targioniaceae and thought that species of Cyathodium would

possibly be found in southern Africa. He misidentified a Riccia collection by Duthie as Cyathodium

sp. (Perold 1 993c). The presence of Cyathodium species in southern Africa has not been confirmed,

HEPATOPHYTA: Targioniineae/Targioniaceae

15

although the genus is widespread in the rest of Africa (Jones 1952). It is distinguished from

Targionia by having thin, delicate thalli with reduced hyaline scales, ill-defined dorsal air pores and

small, saccate, transparent involucres.

TARGIONIACEAE

Targioniaceae Dumort., Analyses des Families des Plantes: 68, 70 (1829); Nees, in Lindl.: 414

(1835).

Targionideae Gray: 678, 680 (1821).

Subfamily TARGIONIOIDEAE

Targionioideae Schiffn. in Engler et Prantl, Natiirliche Pflanzenfamilien edn 1, 1,3: 24-26

(1893).

The diagnoses of the family and of the subfamily Targionioideae [after Grolle (1972) split off

the subfamily Cyathodioideae in the Targioniaceae] are contained in the above description of the

suborder Targioniineae.

TARGIONIA

Targionia (PMicheli) L., Species plantarum 2: 1136 (1753); Gottsche et al.: 574 (1844-1847);

Schiffn.: 26 (1893); Steph.: 763 (1898); Macvicar: 33 (1926); Sim: 16 (1926); Mull.Frib.: 325

(1951-1958); Hassel de Menendez: 68 (1963); S.W.Arnell: 46 (1963a); R.M.Schust.: 66 (1992c);

Perold: 215 (1993c). Type: Targionia hypophylla L.

Thalli in crowded patches or extensive sheets, not in rosettes. Branches simple, sometimes

repeatedly furcate or only apically branched or with ventrolateral innovations; groove absent, thal-

lus dorsally fiat. Scales ventral, in one row on each side of keel, large, obliquely triangular with

long acuminate appendage, dark purple.

Dorsal epidermis hyaline, unistratose, with cell walls thickened, especially at corners; air pores

simple, conspicuous, surrounded by 3 concentric rings of cells. Assimilation tissue with shallow,

single storey of air chambers, containing chlorophyllose filaments; storage tissue well developed,

cells variable in size; occasionally with an oil body.

Asexual reproduction absent.

Autoicous or dioicous. Androecia on terminal disc of short, stipitate, ventrolateral branches,

antheridia with conical protuberances. Gynoecia terminal, below apex of thallus, enclosed in black,

bivalved involucre; capsule subsessile, globose, wall with thickening bands. Spores anisopolar,

ornamentation on distal face with a network of ridges covered by a fine reticulum of smaller ridges;

proximal face with crowded, irregular, reticulated ridges. Elaters usually bispiral. Chromosome

number : n = 9, 27 (in T. lorbeeriana).

Targionia hypophylla is the only representative of the genus in southern Africa. Other taxa

placed here are: T. lorbeeriana Mull.Frib. from the Mediterranean, Australia, California, and ques-

tionably from East Africa and India; T. stellaris (Mull.Frib.) Hassel from Argentina, for which

Schuster (1992c) has created a new subgenus, Prototargionia\ T. elongata from Ethiopia and a new

subspecies, T. hypophylla subsp. linealis W.Frey & Kiirschner (1993) from Saudi Arabia; a new

species was described from India by Udar & Gupta (1983).

16

HEPATOPHYTA: Targioniaceae

mm

HEPATOPHYTA: TARGIONIACEAE

17

Targionia hypophylla L., Species plan-

tarum: 1136 (1753); Steph.: 764 (1898);

Macvicar: 33 (1926); Sim: 16 (1926); Miill.Frib.:

326 (1951-1958); Hassel de Menendez: 69

(1963); S.W.Arnell: 46 (1963a); O.H.Volk: 241

(1979); Piippo: 274 (1991); R.M.Schust.: 70

(1992c); Perold: 215 (1993c). Types: ‘Italia,

Hispania, Constantinopoli’ + citation (syn.);

Dill.: 532. Lichen No. 9, tab. 78, fig. 9. (1741)

(OXF, syn.); (H-SOL, isosyn.) [according to

Isov. (1970) and quoted by Grolle (1976)].

T. michelii Corda in Opiz: 649 (1829). Type: Italy, leg.

Sieber.

T. mexicana Lehm. & Lindenb. in Lehm.: 27 (1832).

Type: Mexico, leg. Schiede.

T. capensis Huebener: 17 (1834).

T. bifurca Nees & Mont, in Mont.: 113 (1838a); Nees:

315 (1838a). Type: Chile, ‘prope Quillota’, leg. Brotero.

T. convoluta Lindenb. & Gottsche in Gottsche et al.: 576

(1846). Type: Mexico, ad Chinantla, leg. Liebman.

T. hypophylla var. capensis Huebener in Krauss: 135

(1846). Circa urbem Capstadt, Augusto.

T. hypophylla vai. fimbriata Miill.Frib.: 326 (1951- 1958).

Thalli medium-sized, in crowded patches;

dark green, rather leathery, faintly areolate, air

pores large, white-encircled, margins purple

and entire to somewhat crenate; when dry, mar-

gins incurved, thalli almost tubular. Branches

simple to repeatedly furcate or with ventrolater-

al or apical innovations, linear to ligulate, up to

30 mm long, 2. 7-3. 5 mm wide, 550 pm thick

medianly, in section 5 or 6 times wider than

thick, apex slightly notched or entire; groove

absent, thallus margins acute, thin; flanks slop-

ing obliquely; ventral face medianly keeled,

mostly deep purple. Scales in 2 ventral rows,

875-1750 pm long, up to 1325 pm wide across

base, tips not, or hardly reaching thallus mar-

gins, obliquely triangular, imbricate, reddish to

dark purple, margins entire or sometimes with

papillae or fimbria, apically continuing into

long-acuminate appendage ± 375 pm long, oil

cells few, scattered.

Dorsal epidermal cells unistratose, hyaline,

rounded to oval, 22.5-37.5 x 17.5-25.0 pm,

with conspicuous trigones; air pores somewhat

raised, simple, oval, 52.5-67.5 x 35.0-40.0

pm, surrounded by 3 concentric rings of differ-

entiated cells: innermost ring with ± 6 small,

thin-walled, collapsed cells, outer 2 rows with

8-1 1 and ± 14 cells in each respectively, slight-

ly thicker-walled. Assimilation tissue ± 80 pm

thick, with air chambers in one storey, contain-

ing simple or branched, 2- or 3-celled chloro-

phyllose filaments, bounding walls hyaline;

storage tissue ± 425 pm thick, cells closely

packed; oil cells scattered throughout tissues.

Asexual reproduction absent.

Autoicous or dioicous. Androecia terminal

on short, ventrolateral branches, sessile discs,

encircled above by low, frilly membrane;

antheridia embedded, opening into conical pro-

tuberances. Gynoecia ventrally displaced below

apex of thallus. Involucres enclosing single cap-

sule, large, shiny black, mussel-like, bivalved,

wall 4-layered, opening along narrow, central,

vertical fissure. Pseudoperianth lacking. Sporo-

phyte subsessile with distinct foot and short seta;

capsule globose, wall with thickening bands,

dehiscence by irregular rupturing. Figure 1.

Spores (47-)62-77(-95) pm diam., light brown

to dark reddish brown, anisopolar; distal face

convex, ornamented with network of ridges,

enclosing 16 or 17 polygonal areas, 12.5-17.5

pm wide, all covered by fine reticulum, alveoli

smaller on sides and crests of primary ridges,

larger within enclosures; proximal face flatfish,

generally with very irregularly contorted, crowd-

ed, reticulated ridges, separated by narrow fis-

sures. Elaters yellowish brown, not tapering but

sometimes branched, bispiral, up to 290 x 12.5

pm. Chromosome number: n = 9. Plate 1A, B.

Figure. 1. — Targionia hypophylla. A-D, thallus: A, dorsal face with tip of involucre protruding at apex; B, with short

ventrally innovating branch bearing terminal disc with antheridia; C, ventral face with pouch-like involucre at apex and 2 rows

of ventral scales; D, cross section. E, F, air pore: E, from above; F, c/s of dorsal cells and chlorophyllose filaments. G, H, scales:

G, margins + intact; H, fimbriate appendage. I, cells of capsule wall with thickening bands. A, C, D, F, I, Koekemoer 477a ; B,

E, G, Garside 6674 ; H, Schelpe 4947. Scale bars: A-D, 1 mm; E, F, I, 50 pm; G, H, 250 pm. Drawings by G. Condy.

18

HEPATOPHYTA: Targioniaceae/Marchantiineae

Targionia hypophylla is a widespread almost

cosmopolitan species, occurring mostly in tem-

perate and seasonally dry areas, on soil in rock

crevices, over rock outcrops or under rock over-

hangs, or as a pioneer on disturbed earth banks,

like road cuttings, sometimes in association

with Riccia spp., Plagiochasma spp. and

Mannia capensis (Steph.) S.W.Amell.

In the FSA area the species has been rather

rarely collected in Namibia [from whence Volk

(1979) recorded 14 collections], Northern

Province, Gauteng, Mpumalanga, Free State,

KwaZulu-Natal, Lesotho, Northern, Western

and Eastern Cape, but frequently in the winter

rainfall areas of the western Northern Cape and

Western Cape. Map 1 .

Targionia hypophylla L. var. fimbriata

Miill.Frib. is not treated as a distinct variety, as

was done by Arnell (1963a) and Hassel de

Menendez (1963), because the presence of fim-

bria along the ventral scale margins is very vari-

able, even in thalli from the same population.

Schuster (1992c) also comments that in his

opinion, ‘the intrapopulational variation in this

feature is so great that no taxonomic segrega-

tion of the two extremes seems possible’.

When fertile, T. hypophylla is recognized by

the ventrally displaced capsule contained in a

shiny black pouch at the apex of the thallus;

sterile plants are distinguished by their dark

green, somewhat leathery appearance, the con-

spicuous white-encircled air pores and reddish

Map 1. — • Targionia hypophylla

□ Lunularia cruciata

to purple-black, obliquely triangular ventral

scales with a single appendage.

Although reported by Arnell (1963a), the

presence of T. lorbeeriana in southern Africa

has not been confirmed. It is distinguished from

T. hypophylla by a strong smell of acid pear

drops when fresh; by the cordate shape and light

green colour of the thallus; by larger, oval air

pores and by having different cell dimensions of

the thallus margins at the apex and dorsal epi-

dermis, as well as the scales in the middle of the

body and below the appendage; the spore orna-

mentation is also different and the chromosome

count is n = 27.

Vouchers: Cholnoky 182; S.M. Perold 898;

Van Rooy 2345, 2961; Volk 11357.

SUBORDER MARCHANTIINEAE

Marchantiineae Limpr., Lebermoose. In F. Cohn, Kryptogamen-Flora von Schlesien: 225 (1876);

Miill.Frib. : 320 (1951-1958); R.M.Schust.: 78 (1992c).

Thalli large to very large, in gregarious patches, not in rosettes; green, glaucous green or dark

green. Branches simple or once to several times furcate, sometimes with apical or ventrolateral

innovations, linear to oblong or obovate, apex entire or notched; groove mostly absent, thallus mar-

gins generally acute; flanks sloping obliquely; ventral face medianly keeled. Scales ventral, small

to large, in 2-4(-6) rows, hyaline or pigmented, shape various, with or without appendages, with

or without oil cells.

HEPATOPHYTA: Marchantiineae

19

Plate 1. — Spores and elater. A, B, Targionia hypophylla: A, distal face; B, proximal face. C, D, Lunularia cru-

ciata: C, spore; D, elater. E, F, Plagiochasma rupestre var. rupestre: E, distal face; F, proximal face. A, B, S.M.

Perold 2365\ C, D, S. Strauss s.n.\ E, G.W. Sim CH1145\ F, Pole Evans 458. A, x 660; B, x 690; C, x 2450; D, x 450;

E, F, x 580.

20

HEPATOPHYTA: MARCHANTIINEAE

Dorsal epidermis generally unistratose, sometimes with bistratose patches; air pores simple,

rarely much raised (in Exormotheca spp.), sometimes compound (in Marchantia spp.).

Assimilation tissue with one (or more) storey(s) of air chambers, rarely subdivided, empty or con-

taining chlorophyllose filaments, very rarely (in Dumortiera) dorsal epidermis and air pores absent;

storage tissue occupying ventral % to almost entire thickness of thallus; rhizoids some smooth, oth-

ers pegged.

Asexual reproduction rarely by discoid gemmae.

Monoicous or dioicous. Androecia mostly sessile, occasionally subsessile, rarely raised on stalk,

antheridia sunken. Gynoecia almost always in distinct stalked receptacles. Stalk short or long, with

or without 1 or 2 rhizoid furrows, sometimes with 1 or 2 bands of air chambers. Involucre bilabi-

ate or bivalved, rarely tubular, occasionally bell-shaped and wide-mouthed, mostly membranous,

often continuous with edges of carpocephalum lobes. Pseudoperianth mostly absent, sometimes

present, divided into cage-like segments or not, and then bell-shaped. Sporophytes with short or

long seta; capsule globose, rarely obovoid, never cleistocarpous, opening by a lid and/or longitu-

dinal valves, wall with or without thickening bands. Spores reticulate or with conical spines, ridges,

bullae or nodules. Elaters long and tapering, bi- or trispiral, rarely short and thick, unispiral or

ringed. Chromosome number: n = 8 or multiples thereof, or 9 or multiples thereof or 10.

Five of the seven families placed here occur in the FSA area.

Key to local families of Marchantiineae

I a Air pores of thallus simple, not or slightly raised, sometimes elevated to ± apices of high-

ly inflated air chambers, surrounded by 1-3(4) concentric rings of differentiated cells,

rarely stellate; male receptacles sessile, often ill-defined; ventral scales in 2 rows;

(crescent-shaped gemma cups only present in Lunularia cruciata ):

2a Air chambers of thallus highly inflated, basally containing chlorophyllose filaments . . .

Exormothecaceae (p

2b Air chambers of thallus not or only slightly raised, with or without chlorophyllose fila-

ments:

3a Air chambers of thallus containing chlorophyllose filaments; crescent-shaped gemma

cups usually present; sporophytes very rare Lunulariaceae (p

3b Air chambers of thallus without chlorophyllose filaments, rarely (in Mannia) subdi-

vided by chlorophyllose supplementary partitions ending in short filaments; gemma

cups absent; sporophytes commonly produced:

4a Plants rare; air pores of thallus (in southern African species) surrounded by 1 ring of

cells, radial walls often thickened and pores stellate; oil bodies absent throughout;

capsule wall with annular thickenings Cleveaceae (p

4b Plants generally common; air pores of thallus usually surrounded by several concen-

tric rings of cells, rarely by 1 ring, pores rarely stellate; oil bodies present; capsule

wall lacking thickenings (except in the very rare Cryptomitrium oreades from

Lesotho, p. 61) Aytoniaceae (p

lb Air pores of thallus compound, surrounded by 6 or 7 superimposed concentric rings of

cells or else lacking, together with dorsal epidermis and air chambers (in Dumortiera

hirsuta ); male receptacle raised on long or rarely on very short stalk; ventral scales in

4-6 rows or rarely vestigial; round gemma cups often present in Marchantia spp. . . .

Marchantiaceae (p

. 72)

.21)

.67)

.25)

• 79)

HEPATOPHYTA: Lunulariaceae

21

LUNULARIACEAE

Lunulariaceae H.Klinggr., Die hoheren Cryptogamen Preussens: 9 (1858); Miill.Frib.: 364

(1951-1958); R.M.Schust.: 80 (1992c). Subtribe Lunulariinae Nees: 9 (1838) (as ‘Lunularieae’).

Type: Lunularia Adans.

Thalli large, in overlying patches; bright green to yellowish green, somewhat glossy. Branches

pseudodichotomously or irregularly furcate, ribbon-like; groove absent, thallus dorsally flat, mar-

gins acute, hyaline; flanks sloping very obliquely; ventral face keeled. Scales ventral, in curved

parallel rows stretched across flanks on either side of keel, hyaline.

Dorsal epidermis hyaline; air pores conspicuous, surrounded by several concentric rings of dif-

ferentiated cells. Assimilation tissue with one low storey of air chambers, containing erect, chloro-

phyllose, branched filaments, floored by chlorophyllose cells; storage tissue well developed; oil

cells scattered throughout tissues.

Asexual reproduction by gemmae produced in crescent-shaped gemma cups.

Dioicous. Androecia with antheridia sunken in thickened, sessile discs, originally terminal,

becoming laterally displaced in a deep notch. Gynoecial receptacles also originally terminal, even-

tually laterally situated; when young, small, sessile, weakly 4-lobed, almost entirely sheathed in

layers of white scales. Stalk elongating when sporophytes nearly ripe, lacking rhizoid furrow.

Involucres tubular, initially drooping, later spreading outwards, cross-like. Pseudoperianth absent.

Sporophytes 1 or 2(3) per involucre, seta long, foot bulbous, capsules obovoid, becoming exsert-

ed, wall lacking thickenings, spores released by shedding tiny distal cap and dehiscing into 4 lance-

olate valves. Spores small, apolar, spherical or ovoid, densely granulate. Elaters long, tapering,

bispiral. Chromosome number: n = 8, 9.

Sporophytes exceedingly rare in southern Africa. The family contains a single genus, Lunularia.

LUNULARIA

Lunularia Adans., Families des plantes 2: 15 (1763); P.Micheli: 4 (1729); Nees: 29 (1838);

Gottsche et al.: 510 (1844 -1847); Schiffn.: 35 (1893); Steph.: 216 (1899); M.Howe: 59 (1899);

Macvicar: 38 (1926); Sim: 123 (1926); Miill.Frib.: 366 (1951-1958); S.W.Arnell: 73 (1963a);

Hassel de Menendez: 125 (1963); R.M.Schust.: 84 (1992c); Perold: 53 (1993a). Type: Lunularia

cruciata (L.) Dumort. ex Lindb.

Selenia Hill: 120 (1773) nom. illeg.

Dichominwn Neck.: 345 (1790) (as subgenus).

Staurophora Willd.: 101 (1809).

Sedgwickia Bowdich: 35 (1825).

Marsilia Kuntze: 837 (1891).

With characters of the family.

Only one species is now recognized although a second species, L. thaxteri , was described from

South America by Evans & Herzog in Herzog (1938); it is now treated as a subspecies by Schuster

(1992c) or as a forma by Hassel de Menendez (1963).

Lunularia cruciata (L.) Dumort. ex Lindb. (1899); Macvicar: 40 (1926); Sim: 24 (1926);

in Notiser Sallskap pro Fauna et Flora Fennica Miill.Frib.: 366 (1951-1958); S.W.Arnell: 73

Forhandlingar 9: 298 (1868); M.Howe: 60 (1963a); Hassel de Menendez: 126 (1963);

22

HEPATOPHYTA: Lunulariaceae

HEPATOPHYTA: Lunulariaceae

23

E.O.Campb.: 31 (1965); R.M.Schust.: 85 (1992c);

Perold: 55 (1993a); Perold: 239 (1995e).

Lunularia vulgaris Micheli: 4 (1729) nom. illegit.

Marchantia cruciata L.: 1 137 (1753). Type: Europe.

Staurophoru pulchella Willd.: 101 (1809) nom. illegit.

Lunularia vulgaris Raddi: 355 (1818) nom. illegit.

Sedgwickia hemisphaerica Bowdich: 35 (1825). Type:

Portugal, Madeira Island, behind Mr Veitch’s Quinta, leg.

Bowdich.

Lunularia michelii Jolis and L. dillenii Jolis: 192 (1853).

Type: Italy, Micheli: Nova plantarum genera: 4, t.4.

Dichominum cruciatum (L.) Trevis.: 785 (1874). Type:

sub Marchantia.

Dichominum vulgare (Raddi) Trevis.: 436 (1877). Type:

sub Lunularia.

Cyathophora cucullata (Mont. & Nees) Kuntze: 834 (1891).

Type: sub Preissia.

Marsilia cruciata (L.) Kuntze: 837 (1891). Type: Europe.

Lunularia thaxteri A.Evans & Herzog in Herzog: 5 (1938).

Type: Chile, Prov. Concepcion, Dep. Coronel: Concepcion,

leg. R. Thaxter( 1905).

Thalli moderately large, in crowded patch-

es; glossy, turning dull with age, bright green

to yellowish green; faintly areolate, air pores

whitish, margins hyaline, irregularly undulate,

somewhat scalloped; when dry, rather leathery.

Branches repeatedly pseudodichotomously or

irregularly furcate with apical or ventrolateral

innovations, ribbon-like, 40-55 mm long,

5(— 1 0) mm wide, 650(-1000) pm thick medi-

anly, in section ± 7-10 times wider than thick,

apex notched or sinusoidal; groove absent,

thallus dorsally flat, margins acute; flanks

sloping obliquely, to becoming slightly re-

curved; ventral face medianly keeled. Scales

in 2 well-spaced rows, stretched across ventral

face of wings, 1000-1375 pm long, up to 4250

pm wide across base, broadly and shallowly

crescentic, hyaline, apically constricted where

joined with rounded appendage, ± 400 x

250-600 pm, margin entire or crenate, ± 20 oil

cells scattered throughout scale and append-

age.

Dorsal epidermal cells unistratose, hyaline,

35-50 x 20-30 pm, thin- to thick-walled or

only thickened at corners; air pores slightly

raised, simple, oval, 17-25 x 12-20 pm, sur-

rounded by 3 or 4 concentric rings of differenti-

ated cells, innermost row often with 4 cells,

outer rings with 10-15 cells in each. Assimi-

lation tissue + 90 pm thick, air chambers in one

storey, containing 3- or 4-celled, branched,

chlorophyllose filaments, bounding walls hya-

line, unistratose, floor densely chlorophyllose;

storage tissue with ± 15(-20) rows of cells

medianly, gradually decreasing in wings; some

cells with pitted walls; oil cells scattered

throughout tissues.

Asexual reproduction by gemmae in cres-

cent-shaped cupules, ± 3 mm wide, with crenate

to entire ridge on proximal side.

Dioicous. Androecia on alternate sides of

thallus, slightly raised, ovate, flattish discs, encir-

cled by membranous sheath with crenate edge,

containing numerous sunken antheridia. Gyno-

ecial receptacles lateral on alternate sides of

thallus, when young small, sessile, domed,

weakly 4-lobed, bearing 4 groups of archegonia

in radiating rows and below attached to thallus,

sheathed in several layers of white scales, upper

edges irregularly fringed with filiform cellular

appendages. Stalk eventually elongating and up

to ± 34 mm long, pale green to whitish, tender, ±

950 pm diam., lacking rhizoid furrow and air

chambers, externally shaggy with scattered,

white, thread-like filaments. Involucres tubular,

rather delicate, enclosing sporophytes carried to

underside of receptacle by expansion of central

dome, initially drooping, later almost horizontal-

ly spreading outwards in a cross. Pseudoperianth

absent. Sporophyte with subspherical foot and

Figure 2. — Lunularia cruciata. A-D, thallus: A, dorsal face with gemma cups; B, female with young archegonio-

phores; C, ventral face with young lateral branch; D, cross section. E, c/s of midrib region, much enlarged; F, G, air pore:

F, c/s dorsal cells and air chamber; G, from above. H, margin of thallus with hyaline cells, seen from above. I, J, scales: I,

older; J, younger. K, 1/s through young archegoniophore; L, 1/s through gemma cup; M, gemma. A, D-H, J, L, M, S.M.

Perold 2R21\ B, C, S.M. Perold 1996. Scale bars: A-C, 2 mm; D, E, K, L, 1 mm; I, J, 500 pm; F, M, 100 pm; G, H, 50 pm.

Drawings by A. Pienaar. Figure 2K partly after Benson-Evans & Hughes (1954: fig. 4).

24

HEPATOPHYTA: Lunulariaceae

Figure 3. — Lunularia cruciata. A, B, androecial disc: A, from above; B, longitudinal section. C, c/s of stalk. D-G,

gynoecial receptacle: D, young receptacle from above; E, older receptacle from side; F, mature receptacle from side; G,

mature receptacle from below. H, 1/s through gynoecial receptacle and upper part of stalk; 1, J, capsule wall: I, cross sec-

tion; J, portion. A-J, S. Strauss 64. Scale bars: A, 2 mm; B, D-H, 1 mm; C, 100 pm; I, J, 50 pm. Drawings by M. Steyn.

rapidly elongating seta, supporting obovoid cap-

sule (1-3), exserted beyond involucre, capsule

wall unistratose, lacking thickenings, dehiscence

by shedding tiny distal bistratose cap and lance-

olate valves folding back. Figures 2 & 3. Spores

(1 2.5-) 15.0-22.5 pm diam., apolar, triradiate

mark absent, mostly spherical or ovoid, light

brown, wall thin, densely granulate. Elaters light

brown, bispiral, long-tapering at both ends, 320-

350 pm long, in centre 5-6 pm wide, at tips 2.5

pm. Plate 1C, D. Chromosome number, n = 8

(Heitz 1927); n = 9 = 8 + x/y2 (Lorbeer 1934); n

= 9 (Bornefeld 1987).

A widespread species, L. cruciata is known

from North and South America, the Mediter-

ranean region, Asia, central and southern Africa,

Australia and New Zealand. In the FSA area

HEPATOPHYTA: Lunulariaceae/Aytoniaceae

25

many collections are from nurseries or city gar-

dens, so it would appear that L. cruciata may

have been introduced into southern Africa. It is

not frequently found here, most collections being

from the southern Western Cape, a few from

Gauteng and some from KwaZulu-Natal. Map 1 .

Lunularia cruciata is easily recognized

because of the crescent-shaped gemma cupules

that are always present.

Vouchers: Perold 645; Sim 1279 , 1280; Stir-

ton 9415.

AYTONIACEAE

Aytoniaceae Cavers in New Phytologist 10: 42 (1911). Type: Aytonia G.Forst. (= Plagiochasma

Lehm. & Lindenb.).

Grimaldieue Rchb. ex Rabenh.: 6 (1848).

Grimuldiaceue (Rchb. ex Rabenh.) Miill.Frib.: 220 (1940b).

Thalli smallish to large, in dense or loose patches; dull, glaucous green and waxy to velvety, or

shiny, lime-green to bright green, firm or somewhat spongy. Branches simple to pseudodichoto-

mously or variously furcate, sometimes articulate with ventrolateral or apical innovations, Ungu-

late, apex notched or entire, tips of apical scales often recurved over edge; groove absent, thallus

dorsally flat or slightly concave, margins acute, mostly purple or black, scalloped or sometimes

irregularly crenate; flanks sloping obliquely, sometimes black and shiny; ventral face medianly

keeled or rounded. Scales ventral, in 2 rows, one on either side of keel, generally large, body ovate

to obliquely triangular or transversely rectangular, apically with lanceolate, ovate, orbicular or fil-

iform appendages, rarely constricted at base, mostly purple, reddish or black, scattered oil cells pre-

sent throughout.

Dorsal epidermis mostly lacking chloroplasts, thin- or thick-walled, with or without trigones;

air pores simple, sometimes stellate, very small and inconspicuous to large and slightly raised, sur-

rounded by up to 3 concentric rings of (4)5-8 cells in each. Assimilation tissue with air chambers

almost always empty, single or storeyed, mostly shallow, rarely tall; storage tissue well developed,

occupying ventral V2 or more of thallus.

Asexual reproduction absent.

Monoicous, autoicous or paroicous, rarely dioicous. Androecia on main or on reduced ventrolat-

eral branches, with antheridia sunken into thallus dorsally, in clusters or rows or in sessile discs or

cushions, base sometimes encircled by short paleae. Gynoecial receptacle raised on stalk, sometimes

arising terminally at apical notch and mostly inhibiting further growth of branch, rarely ventrolater-

ally, or more usually, dorsally at intervals along length of main branch; carpocephala domed, disci-

form or variously lobed, with compound air pores. Stalk short or long, with or without rhizoid fur-

row, with or without air chambers, at base and summit with or without paleae. Involucre swollen and

bilabiate, or membranous and bell-shaped. Pseudoperianth sometimes present, with cage-like seg-

ments. Sporophyte with short seta, foot rounded, capsule globose, wall mostly lacking thickenings,

dehiscence by shedding small, well-defined apical lid or by an irregularly decaying, usually bistratose

cap. Spores alveolate, with thick or thin walls, and then with subsidiary alveoli, or with swollen bul-

lae, or ridges, always winged. Elaters tapering, bi- or trispiral. Chromosome number: n = 9, 10, 18.

Two subfamilies are recognized, Aytonioideae and Reboulioideae Grolle (p. 43).

26

HEPATOPHYTA: AYTONIACEAE

A key to the two subfamilies is not included, but a key to the local genera and two of the species

of the Aytoniaceae is given, as Plagiochasma is the only local genus referred to the Aytonioideae.

Subfamily AYTONIOIDEAE

Thalli medium-sized to large, in crowded, extensive mats; dull glaucous green or purplish, then

waxy to velvety, otherwise bright green to yellowish green, firm and somewhat leathery. Branches

simple or pseudodichotomously to variously furcate, with ventrolateral or apical innovations,

sometimes articulate, lingulate, apex mostly notched with scale appendages recurved over edge;

groove absent, thallus dorsally flat, margins thin, attenuate, narrowly purple, scalloped; flanks slop-

ing obliquely to very obliquely, purple or dark red; ventral face medianly keeled. Scales ventral, in

2 rows, one on either side of keel, body broadly ovate, apically with linear-lanceolate or ovate to

orbicular appendage, sometimes constricted or folded at base, purple-red to violet, scattered oil

cells present throughout.

Dorsal epidermis mostly lacking chloroplasts, cells thin- or thick-walled, with or without

trigones, roughened or smooth, with or without waxy granular deposit externally; air pores simple,

sometimes stellate, minute and inconspicuous or larger and slightly raised, surrounded by 1 or 2(3)

concentric rings of (4)5-8 cells in each, radial walls often forming ± continuous lines, sometimes

thickened. Assimilation tissue with small, empty air chambers, in several irregular storeys, cells in

bounding walls chlorophyllose; storage tissue with closely packed cells.

Monoicous, autoicous or paroicous. Androecia away from branch apex, with antheridia sunken

in tumid, sessile, crescentic to broadly U- or V-shaped, dorsal cushions, base encircled by short

paleae. Gynoeciat receptacle(s) single to several along main branch away fron apex, usually with

tuft of slender paleae around base, eventually transferred to apex of stalk; carpocephalum with top

slightly raised or nearly flat or ± depressed, 3- or 4-sided. Stalk very short to long, lacking rhizoid

furrow. Involucre bilabiate, with vertically, slightly overlapping, somewhat swollen lips. Pseudo-

perianth absent. Sporophyte with short seta, capsule globose, wall thickenings lacking, dehiscing

by irregularly decaying lid. Spores triangular-globular, winged, both faces coarsely alveolate.

Elaters long, tapering, bi- or trispiral. Chromosome number, n = 9, 18.

Only the genus Plagiochasma is classified in the subfamily Aytonioideae.

Key to local genera and two species of Aytoniaceae

la Thalli often large, firm and leathery; air pores minute to large, surrounded by 1 or 2(3)

concentric rings of cells; carpocephala dorsal on thallus, away from apex; stalk some-

times very short, always lacking rhizoid furrow Plagiochasma

lb Thalli generally smaller, often thin and somewhat delicate; air pores medium-sized, sur-

rounded by 2 or 3 concentric rings of cells; carpocephala on stalk arising from apical

notch of thallus oral bifurcation of branches, very rarely ventrolaterally, with 1 rhizoid

furrow:

2a Air chambers of thallus much subdivided by supplementary chlorophyllose partitions

Mannia capensis (p. 65)

2b Air chambers of thallus empty, not subdivided, lacking chlorophyllose filaments, cells

in bounding walls with chloroplasts:

HEPATOPHYTA: Aytoniaceae

27

3a Carpocephala always with basket-like pseudoperianths, divided into lanceolate seg-

ments; capsule wall lacking thickenings; stalk arising from apex of thallus or at

bifurcation of branches Asterella (p. 43)

3b Carpocephala lacking pseudoperianths; capsule wall with thickenings; stalk arising ven-

trolaterally Cryptomitrium oreades (p. 61)

PLAGIOCHASMA

Plagiochasma Lehm. & Lindenb. in Lehm., Novarum et minus cognitarum stirpium pugillus quar-

tus: 13 (1832); Nees: 33, 40 (1838); Gottsche et al.: 511 (1844-1847); Steph.: 775 (1898);

A. Evans: 262 (1915); Sim: 16 (1926); Miill.Frib.: 331 (1951-1958); Hassel de Menendez: 83

(1963); S.W.Arnell: 65 (1963a); Bischl.: 71 (1977); R.M.Schust.: 264 (1992c); Perold: 13, 14

(1995a). Type: P. cordatum Lehm. & Lindenb.

Aytonia J.R.Forst. & G.Forst. in G.Forst.: 147 (1776); Lindb.: 291 (1868); Schiffn.: 30 (1893). Type: A. rupestris.

Aitonia J.R. Forst. & G.Forst. in G.Forst.: 46, 73 (1787) orth. var. [not of Thunb.: 166 (1776)].

Rupinia L.f.: 69 (1781) nom. illegit.

Ruppinia L.f.: 204 (1783) orth. var. Type species R. rupestris.

Antrocephulus Lehm.: 682 (1838). Type: A. nepalensis.

Teldea Mont, ex Webb & Berthel.: 59 (1840) nom. illegit. Type: T. elasticu.

With characters of the subfamily Aytonioideae (p. 26).

Two subgenera, namely Micropylum and Plagiochasma have been instituted by Bischler (1977),

based mainly on the compactness and colour of the thalli, the structure of the dorsal air pores and

on the shape, size and margins of the scale appendages.

Key to subgenera and species of Plagiochasma

la Thalli glaucous to greyish green, dull and velvety, dorsally granular, with numerous air

pores, tiny and obscure, surrounded by a single ring of 4-6 cells but never by an inner

hyaline ring of collapsed cells; ventral scales with 1, 2(3) narrow appendages, hardly

or not constricted at base, with margins not differentiated and lacking teeth and/or

papillae . . . subgenus Micropylum Bischl.):

2a Ventral scales reddish pink to purple, rarely more than 2000 pm long, including pink,

purple or hyaline appendage(s) (1 or 2), narrowly to broadly triangular, up to 900 pm

long, apically shortly pointed, with 1 or 2 (rarely 3) cells in series, thin-walled and

quadrate or rectangular; spores up to 92.5 pm diam la. P. rupestre var. rupestre

2b Ventral scales dark red or purple, large, up to 3000 pm long, including hyaline

appendage(s) (1-3), narrowly triangular, up to 1500 pm long, apically with a long

point, with 3-5 elongated cells in series, thick-walled; spores more than 92.5 pm

diam lb. P rupestre var. volkii

lb Thalli green to yellow-green, shiny and dorsally smooth with fewer air pores, large and

quite conspicuous, raised and surrounded by an inner hyaline ring of collapsed cells

and then by 2 or 3 concentric rings of 5-8 cells in each; ventral scales with 1-3

appendages, wide or narrow, often constricted or folded at base with margins differen-

tiated into smaller cells, teeth and/or papillae . . . subgenus Plagiochasma, p. 33):

28

HEPATOPHYTA: Aytoniaceae

3a Scales mostly with 1 appendage, sometimes with two, round or oval or broadly trian-

gular, widest across middle, constricted or folded at base; along margins 1 or 2 rows

of regular, smaller cells or alternating with them, cells of usual size, lacking teeth;

elaters with evenly thickened spirals:

4a Thalli robust; carpocephalum on short, thick stalk; scale appendage single, rarely

double, rounded, large, hyaline above, red or pink below, markedly constricted at

base; margins smooth, with small cells here and there alternating with somewhat

larger ones 2. P. appendiculatum

4b Thalli medium-sized; small carpocephalum on thin, short or long stalk; scale

appendage single or double, oval or broadly triangular, pink or violet, slightly con-

stricted or folded or horizontally pleated at base; margins with 1 or 2 rows of

smaller, regular cells, occasionally with papillae

3. P. microcephalum var. microcephalum

3b Scales with 1, 2 (or 3) appendages, narrowly triangular, slightly constricted to folded

at base or evenly tapered; sometimes toothed along margins; elaters with spirals

interrupted or evenly thickened:

5a Thalli robust but carpocephala relatively small; dorsal air pores of thalli surrounded

by hyaline ring and 3 concentric rings of cells; scale appendages red, not acumi-

nate, slightly constricted or folded at base; elaters with spirals often interrupted

4. P. eximium

5b Thalli less robust and carpocephala of usual size; air pores surrounded by hyaline ring

and 2 concentric rings of cells; scale appendages purple, acuminate, lanceolate,

not constricted at base; elaters with spirals evenly thickened 5. P. beccarianum

Subgenus Micropylum Bischl.

Thalli glaucous-green, dull, velvety, firm, covered with water-repellent, granular deposit. Scales

with acuminate appendages, margins undifferentiated, lacking teeth and papillae.

Dorsal epidermis with air pores numerous, tiny and inconspicuous, lacking surrounding small,

inner hyaline ring of collapsed cells.

Only Plagiochasma rupestre with two varieties is placed here.

1. Plagiochasma rupestre (J.R.Forst. &

G.Forst.) Steph. in Bulletin de l’Herbier

Boissier 6: 783 (1898). Mull.Frib.: 332 (1951-

1958); A. Evans: 277 (1915); Sim: 18 (1926);

Hiissel de Menendez: 84 (1963); S.W.Arnell:

67 (1963a); Bischl.: 264 (1978); O.H.Volk: 237

(1979); Bischl. & Sergio: 173 (1984); R.M.

Schust.: 292 (1992c); Pcrold: 14 (1995a). Type:

Madeira, Funchal, Quinta do Bom Sucesso,

Sergio & Ndbrega 3873 [LISU, neo.! selected

by Bischl. & Sergio (1984); PC, BM, G,

MADJ, iso.].

Aytonia rupestris J.R.Forst. & G.Forst.: 147 (1776);

Lindb.: 291 (1868); Schiffn : 30 (1893).

P. dschallanum Steph : 778 (1898). Type: Tanzania,

Kilimandscharo, ad lacum Dschalla, leg. Holst.

P. tenue Steph.: 779 (1898). Types: S. Africa, Transvaal,

leg. MacLeci, Wilms', Tanzania, Usambara, leg. Holst',

Angola, leg. Welwitsch.

P. algericum Steph.: 780 ( 1 898). Type: Algeria, leg. Trabut.

P. muricatum Steph.: 310 ( 1901a) nom. illegit.

P. abyssinicum Gola: 62 (1914). Type: Ethiopia,

Erythraea, in regione Hamasen prope Asmara n. 132, 24. IV.

1909, leg. Chiovenda.

P. capense Siin: 17 (1926). Type: S. Africa, Herschel,

Cape Province, 5000 ft, leg. Hepburn.

The list of synonyms includes only African

plants and was taken from Bischler (1978).

HEPATOPHYTA: AYTONIACEAE

29

Thalli medium-sized to large, in gregarious

patches; firm, leathery, glaucous to greyish

green, dull, surface ± water-repellent, hardly

areolate, air pores almost imperceptible, mar-

gins purple, scalloped and undulate; when dry,

margins incurved. Branches simple or once,

rarely twice furcate or articulate with apical or

ventrolateral innovations, oblong to ligulate,

8-25 mm long, (3— )4— 6 mm wide, 375-650 pm

thick medianly, in section 9 or 10 times wider

than thick, apex notched, acute scale append-

ages recurved over edge; groove absent, thallus

dorsally flat, margins acute, thin; flanks sloping

obliquely; ventral face medianly keeled, green.

Scales in 2 ventral rows, asymmetric, obtusely

triangular, reddish pink or purple, sometimes

partly hyaline, body 600-1500 pm long, mar-

gins lacking teeth and papillae, base flatly

arched, 900-1250 pm wide, narrowed above

without constriction to acuminate or ovate-

lanceolate appendage, 900-1450 pm long, oil

cells scattered throughout.

Dorsal epidermal cells unistratose, hyaline,

polygonal, 25—47 x 20-37 pm, thin-walled,

thickened at corners, externally covered with

granules; air pores not raised, simple, tiny, ap-

pearing plugged, numerous, surrounded by one

ring of 3-5 small cells, radial walls often thick-

ened, lacking small inner hyaline ring of col-

lapsed cells. Assimilation tissue 175-220 pm

thick, air chambers empty, in several storeys, cells

in bounding walls containing chloroplasts; stor-

age tissue well developed; oil cells scattered

throughout tissues.

Monoicous. Androecia medianly on leading

branch or on apical or ventrolateral innova-

tions, sessile cushions, round or crescentic,

base encircled by tapering, purple paleae,

antheridia sunken, opening above into raised

conical papillae. Gynoecial receptacles in

acropetal sequence medianly along main

branch, or paired on furcate branches, enclosed

by tall tuft of tapering, purple-red paleae, most

of them later carried to top of stalk; car-

pocephala 2-3 mm wide, on top initially slight-

ly raised, later becoming depressed, air pores

compound, below with 1— 3(— 5) lobes. Stalk at

maturity usually remaining very short, only

rarely up to 6 mm long, ± 640 pm wide, lack-

ing rhizoid furrow and air chambers. Involucre

bilabiate, lips vertical and swollen, slightly

overlapping. Sporophyte with short seta, cap-

sule ± globose, wall unistratose, lacking thick-

ening bands, dehiscing by decaying lid. Spores

80-105 pm diam., triangular-globular, polar,

light brown to yellow brown; wing ± 12 pm

wide, margin undulate, crenulate; ornamenta-

tion similar on 2 faces; distal face with ± 4

alveoli across, ± 20 pm wide, walls wide and

studded with granules; proximal face with nar-

row triradiate mark, each of 3 facets with 6-9

alveoli, up to 25 pm wide, walls raised and

wide, studded with granules. Elaters light

brown to yellow brown, 175-235 pm long,

12.5 pm wide in middle, tapering toward ends,

± 5 pm wide, bispiral. Chromosome number: n

= 9, 18 (Bischler 1978).

Two varieties are recognized: P. rupestre var.

rupestre and P. rupestre var. volkii. They are

distinguished by the longer, acuminate, hyaline

appendages of the ventral scales and slightly

larger spore dimensions of var. volkii.

la. P. rupestre var. rupestre

Ventral scales obliquely lunate, rarely longer

than 2000 pm, 1050 pm wide across base; 1 or

2 narrowly to broadly triangular appendages up

to 900 pm long, 1 .7-2.7 times longer than wide,

apically acuminate with uniseriate 1 or 2(3) ter-

minal cells, margins entire. Male paleae around

base of androecium 550-580 pm long, 110-180

pm wide at base, tapering to narrow tip, with

1-3 cells in series; female paleae 1030-1375

pm long, 150-220 pm wide at base, tapering to

narrow tip, with up to 4 cells in series. Figure

4A-N. Spores 80.0-92.5 pm diam. Plate IE, F.

The typical variety is subcosmopolitan and

widely distributed, especially in xerothermic

regions. In the FSA area P. rupestre var.

rupestre is quite common and frequently col-

lected in rocky crevices, moist ledges, under

boulders, or at seepages, on calcareous sub-

strates or on soil overlying cave sandstone or

HEPATOPHYTA: Aytoniaceae

HEPATOPHYTA: Aytoniaceae

31

dolomite. It sometimes grows together with

Targionia hypophylla and Riccia spp. It is

known from Namibia, Botswana, Northern

Province, North-West, Gauteng, Mpumalanga,

Free State, KwaZulu-Natal, Lesotho, Northern,

Western, and Eastern Cape. Map 2.

Plagiochasma rupestre var. rupestre is easi-

ly identified by its dull, velvety and glaucous

thalli with simple, very inconspicuous pores

and by its reddish pink or purple scales, with

ovate-lanceolate or acuminate appendages and

entire margins.

Vouchers: Brusse 4123; Condy 45; Germis-

huizen 5393; Perold 2167; Van Rooy 2726.

lb. P. rupestre var. volkii Bischl. Type:

Namibia, Neudamm bei Windhoek, Volk 948 (JE).

Ventral scales larger, up to 3000 x 1350 pm,

more conspicuous than those of typical variety,

especially 2 or 3 hyaline or white appendages,

which are narrowly triangular, 1370-1450 pm

long and 4 or 5 times longer than wide; apex

rather fragile, 3-5 elongated cells in series,

walls thickened. Male paleae ± 600 pm long,

150 pm wide at base, tapering to narrow tip

with 4 cells in series; female paleae up to 1500

pm long, 100-150 pm wide at base, tapering to

a narrow tip with 3 or 4 cells in series. Figure

40-R. Spores 92.5-105.0 pm diam., slightly

larger but very similar in appearance to those of

typical variety. Plate 2A, B.

This variety is quite rarely collected in

southern Africa, but both varieties grow togeth-

er fairly frequently. In the FSA area P. rupestre

Map 2. — • Plagiochasma rupestre var. rupestre

□ P. rupestre var. volkii

var. volkii is known from Namibia, Northern

Province, North-West, Gauteng and KwaZulu-

Natal. Map 2.

Bischler (1978) had also studied plants from

the Western Cape, Free State, Lesotho and

Zimbabwe; it therefore occurs throughout most

of southern Africa. Schuster (1992c) states that

P rupestre var. volkii also occurs in Peru and

Argentina and it is accordingly not endemic to

southern Africa.

In P. rupestre var. volkii the thallus is gener-

ally somewhat narrower than in the typical vari-

ety, but otherwise it is very similar in colour,

appearance and composition. The very long,

decolorate scale appendages are conspicuous,

however, and make it easily separable.

Vouchers: H. Anderson CHI 3512; Glen 1644;

Mogg 37590; Perold 2586; Volk 00948.

Figure 4. — A-N, Plagiochasma rupestre var. rupestre: A, E, F, thallus: A, dorsal face with archegoniophore and car-

pocephalum; E, ventral face; F, cross section. B, carpocephalum, side view; C, c/s of stalk; D, androecium at apex of ven-

trolateral branch. G, H, air pore: G, dorsal cells from above; H, c/s of dorsal cells and air chambers. I, margin of thallus.

J, K, scales: J, with 2 appendages; K, with 1 appendage. L, cells in capsule wall; M, female paleae; N, male palea. O-R,

Plagiochasma rupestre var. volkii: O, P, scales: O, with 1 appendage; P, with 2 appendages. Q, male palea; R, female

palea. A, B, D, E, L, N, Heilgendorff CHI 3611 ; C. Manning CHI 3590', F, H, H. Anderson 1230', G, I-K, M, S.M. Perold

3058', O-R, Mogg 37590. Scale bars: A, B, D, E, 2 mm; F, 1 mm; C, J, K, M-R, 250 pm; G-I, L, 50 pm. Drawings by G.

Condy.

32

HEPATOPHYTA: Aytoniaceae

Plate 2. — Spores. A, B, Plagiochasma rupestre var. volkii: A, distal face; B, proximal face. C, D, P. appen-

diculatum: C, distal face; D, proximal face. E, F, P. microcephalum var. microcephalum: E, distal face; F, prox-

imal face. A, B, Mogg 37590, C, Hook 8204, D, Perold & Koekemoer 3135', E, F, Holst 362. A, B, x 520; C, x

630; D. x 700; E, x 770; F, x 750.

HEPATOPHYTA: AYTONIACEAE

33

Subgenus Plagiochasma

Thalli green or yellow-green, less compact than in subgenus Micropylum, dorsally ± smooth,

faintly areolate. Scales and appendage margins differentiated with smaller cells, teeth or papillae.

Dorsal epidermis with air pores quite large, surrounded by collapsed hyaline ring and 2 or 3 con-

centric rings of cells, radial walls generally forming ± continuous radiating lines, sometimes thickened.

The other Plagiochasma species are assigned here.

2. Plagiochasma appendiculatum Lehm.

& Lindenb. in Lehm., Novarum et minus cogni-

tarum stirpium pugillus quartus: 14 (1832);

Gottsche et al.: 517 (1844-1847); Steph.: 782

(1898); Kashyap: 318 (1914); Bischl.: 228

(1978); Perold: 19 (1995a). Type: Nepal, Punjab,

Dehra Doon, Wallich.

P.fischerianum (Steph.) Steph.: 786 (1898) (P. fischeri).

Type: Kenya, Ligaijo, Fischer 692 [as Aitonia fischeriana

Steph.: 301 (1895)].

P. appendiculatum Lehm. & Lindenb. var. erythraeum

Gola: 62 (1914). Type: Ethiopia, Eritrea, Hamasen, sul

Monte Bizen nella valle Nabaret a Mai Electi, Ragazzi 253.

For a complete synonymy see Bischl. (1978).

Thalli robust, in gregarious patches; bright

green, shiny, areolate, air pores small, faintly

visible, margins purple, scalloped and slightly

undulate; when dry, margins tightly incurved.

Branches simple or once, sometimes twice fur-

cate, rarely articulate with apical or ventrolater-

al innovations, broadly lingulate, 10-20 mm

long, 5-8 mm wide, 750-925 pm thick median-

ly, in section 6-8 times wider than thick, apex

notched with large, orbicular appendages re-

curved over edge; groove absent, thallus mar-

gins acute, thin; flanks sloping very obliquely;

ventral face medianly keeled, green. Scales in 2

ventral rows, body up to 1250 pm long, margins

occasionally with projecting papillae, base flat-

ly arched, ±1100 pm wide, gradually narrowed

above, deeply constricted and folded where

joined with large, mostly single, orbicular, often

decolorate appendage, 750 pm long, 550 pm

across widest part, margins smooth with 1 or 2

rows of small rectangular cells, alternating with

somewhat larger cells, some smaller oil cells

scattered throughout scale.

Dorsal epidermal cells unistratose, hyaline,

thin-walled, thickened at corners, polygonal,

22.5-42.5 x 15.0-27.5 pm, smooth externally;

air pores slightly raised, simple, 7.5-10.0 pm

wide, surrounded by innermost ring of tiny, col-

lapsed cells, then by 2 (or 3 partly) concentric

rings of 5 or 6 larger cells in each, radial walls

not thickened. Assimilation tissue 375-500 pm

thick, air chambers empty, in several storeys,

bounding walls chlorophyllose; storage tissue

well developed; oil cells scattered throughout

tissues.

Monoicous, but male and female receptacles

often on separate plants. Androecia medianly on

leading branch near apex, sessile cushions,

oval, horseshoe- or heart-shaped, base encircled

by blunt, hyaline or partly purple paleae,

550-580 x 130-180 pm. Gynoecial receptacles

medianly along main branch, single or several

in acropetal sequence, initially enclosed by

arching, hyaline paleae, ± 850 x 120 pm; car-

pocephala 2x2 mm when 4 lobes present. Stalk

1.25-2.00 mm long, ± 750 pm wide. Involucre

bilabiate. Sphorophyte with capsule ± globose.

Figure 5. Spores 75-85 pm diam., triangular-

globular, polar, light brown, translucent; wing ±

10 pm wide, porate at corners, margin undulate,

finely crenulate; ornamentation similar on 2

faces; distal face with 5 alveoli across, ± 22 pm

wide, walls finely granular; proximal face with

very narrow triradiate mark, each of 3 facets

with 6 or 7 alveoli, walls wide and studded with

granules. Elaters pale brown, 187-240 pm

long, 10 pm wide in middle, tapering toward

ends, 5 pm wide, bi- or trispiral. Chromosome

number : n = 9 (Bischler 1978). Plate 2C, D.

Plagiochasma appendiculatum is chiefly an

Asiatic species and has been reported from

34

HEPATOPHYTA: Aytoniaceae

HEPATOPHYTA: Aytoniaceae

35

Afghanistan, Burma, Celebes, China, Taiwan

[Formosa], India, Kashmir, Nepal, Pakistan,

Philippines, Sikkim and Vietnam. It is also

known from the Arabian Peninsula, Socotra and

Yemen, and in Africa from Ethiopia, Kenya,

Tanzania and Zimbabwe. In southern Africa the

species is very rare and has been collected at

only two localities in the North-West. Map 3.

Generally P appendiculatum is a large plant

and easily recognized by its mostly single, very

rarely double, large, orbicular scale appendages.

Vouchers: Bottomley CH268; Perold 854;

Perold & Koekemoer 3135.

3. Plagiochasma microcephalum (Steph.)

Steph. var. microcephalum in Bulletin de

l’Herbier Boissier 6: 781 (1898); Bischl.: 237

(1978); O.H.Volk: 240 (1979); Perold: 21

(1995a).

Aitonia microcephala Steph.: 301 (1895b). Type: Tanza-

nia, Usambara, leg. Holst 362 (G, holo.!).

P. dinteri Steph.: 762 (1901b). Type: Namibia (=

Deutsch-Siidwest-Afrika). Hereroland: Kransfontein, leg.

Dinter.

Thalli smallish to medium-sized, in gregari-

ous patches; bright green, finely and irregular-

ly areolate, air pores faintly visible, margins

red-brown to purple, scalloped; when dry, mar-

gins tightly inflexed. Branches simple to sever-

al times pseudodichotomously furcate, occa-

sionally with apical or ventrolateral innova-

tions, ligulate to oblong, 6-12 mm long,

3-4(-6) mm wide, 450-850 pm thick median-

ly, in section 6 or 7 times wider than thick,

apex notched, broadly ovate, purple or partly

decolorate scale appendages recurved over

edge; groove absent, thallus dorsally flat, mar-

gins acute, thin; flanks sloping obliquely, deep

purple or dark red; ventral face medianly

keeled, green. Scales in 2 rows, asymmetric,

Map 3. — O Plagiochasma appendiculatum

▲ P. microcephalum var. microcephalum

• P. eximium

□ P. beccarianum

obliquely triangular, purple or reddish, body up

to 675 pm long, margins with few projecting

papillae, base flatly arched, 800-1500 pm

wide, narrowed above and constricted or fold-

ed or transversely pleated, where joined with 1

or sometimes 2 broadly ovate or triangular

appendages, 350-600 pm long, 350-450 pm

across middle, along margins with 1 or 2 rows

of small, thin-walled, regular cells, occasional-

ly with a projecting papilla, a number of small-

er oil cells scattered throughout scale.

Dorsal epidermal cells unistratose, hyaline,

polygonal, 22.5-35.0(^10.0) x 17.5-25.0 pm,

thin-walled, but with trigones, smooth external-

ly; air pores slightly raised, simple, 7.5-12.5

pm wide, surrounded by innermost ring of

small, collapsed cells, then by 2 concentric

rings of 5-7(8) larger cells in each, radial walls

sometimes thickened. Assimilation tissue

200^100 pm thick, air chambers empty, in sev-

eral storeys, bounding walls chlorophyllose;

storage tissue well developed; oil cells scattered

throughout tissues.

Figure 5. — Plagiochasma appendiculatum. A-D, thallus: A, dorsal face with archegoniophore and carpocephalum; B,

dorsal face with androecium; C, ventral face; D, cross section. E, F, air pore: E, c/s dorsal cells and air chambers; F, with

surrounding cells from above. G, margin of thallus; H, I, scales; J, scale appendage; K, c/s of stalk; L, male paleae; M,

female paleae. A, C, F, G, K, M, Bottomley CH268\ B, D, E, H-J, L, S.M. Perold 854. Scale bars: A-C, 2 mm; D, 1 mm;

E-G, 50 pm; H-M, 250 pm. Drawings by G. Condy.

HEPATOPHYTA: Aytoniaceae

HEPATOPHYTA: AYTONIACEAE

37

Monoicous. Anclroecia medianly spaced

along length of thallus, small sessile cushions,

rounded or V-shaped, basally encircled by

inconspicuous purple, tapering paleae, ± 400 x

200 pm, several mucilage papillae at margins

and apex. Gynoecial receptacles acropetally

arranged along length of thallus and alternating

with androecia, initially enclosed by arching,

tapering, hyaline or purple paleae, ± 500 x 150

pm, sometimes marginally with few mucilage

papillae; carpocephala small, 1.0 x 2.0 mm,

when 2 lobes present. Stalk up to 15 mm long,

±310 pm wide, variously twisted, striate and

dark red. Involucre bilabiate. Figure 6. Spores

70-75 pm diam., triangular-globular, polar,

light brown; wing ± 10 pm wide, margins undu-

late, finely crenulate; ornamentation similar on

2 faces; distal face with 4 alveoli across, 15-20

pm wide, walls narrow, almost smooth to gran-

ular; proximal face with distinct triradiate mark,

arms thin, 5.0-7. 5 pm high, 4 alveoli on each of

3 facets, walls almost smooth to granular.

Elaters light brown, 212-300 pm long, 7.5 pm

wide in middle, tapering toward ends, ± 5 pm

wide, bi- or trispiral. Chromosome number: n =

9 (Bischler 1978). Plate 2E, F.

Bischler (1978) recognized two varieties of

P microcephalum, namely var. microcephalum

and var. tunesicum Bischl. The latter appears to

be restricted to Tunisia, whereas she reported the

former from the following African countries:

Ethiopia, Uganda, Angola, Namibia and South

Africa. It is also known from Madagascar,

Yemen and southwest India. In southern Africa

the species has infrequently been collected in

Namibia, Northern Province, North-West,

Gauteng and Northern Cape. Map 3.

Plagiochasma microcephalum can be distin-

guished by the green colour of the fresh thallus

and by the generally large, broadly ovate or tri-

angular scale appendages which have one or

two rows of smaller cells along the margin.

Bischler (1978) reported that plants growing in

dry habitats have scales with a single, broadly

ovate appendage which is constricted at the

base, whereas those from more humid sites usu-

ally have one or two triangular scale append-

ages horizontally folded at the base and hardly

constricted. Plants with mature female recepta-

cles are rare. The carpocephala are small (hence

the specific epithet) and are raised on a slender,

short or long, dark red stalk.

Vouchers: Bottomley CHI 75; Burtt Davy

15176; Perold 2976; Volk 81/183.

4. Plagiochasma eximium (Schiffn.)

Steph. in Bulletin de l’Herbier Boissier 6: 781

(1898); Bischl.: 248 (1978); Perold: 23 (1995a).

Aitonia eximia Schiffn. in Steph.: 300 (1895b). Type:

Kainerun, Buea, an den Hohlen eine Stunde ostlich von

Manus-Quelle, 2 500 m, 4-II-1891, leg. Preuss 731 (FI,

lecto.!).

P. schimperi Steph.: 788 (1898). Type: Ethiopia (Abys-

sinia). In monte Semen, leg. Schimper.

Grimaldm abyssinica Gola: 63 (1914). Type: Abyssinia,

leg. Chiovenda 2993 (FI).

Thalli robust, in gregarious patches; yellow-

green, finely and irregularly areolate, air pores

faintly visible, margins narrowly to widely dark

red, scalloped and undulate; when dry, margins

tightly inflexed. Branches simple or once pseu-

dodichotomously furcate, sometimes articulate

with one or more apical innovations, 16.5-22.0

mm long, 5.0-8. 5 mm wide, + 750 pm thick

medianly, in section 7-11 times wider than

thick, apex notched, with lanceolate, reddish

pink or dark red scale appendages recurved

over edge; groove absent, thallus margins acute,

thin; Banks sloping obliquely; ventral face

medianly keeled, green. Scales in 2 ventral

rows, asymmetric, obtusely triangular, deep pink

Figure 6. — Plagiochasma microcephalum var. microcephalum. A, B, E, thallus: A, dorsal face with young recepta-

cles; B, ventral face; E, cross section. C, carpocephalum on stalk; D, c/s of stalk. F, G, air pore: F, c/s dorsal cells and air

chambers; G, dorsal cells from above. H, margin of thallus. I-L, scales: I, with 2 appendages; J, with I appendage; K, L,

appendages. M, male paleae; N, female paleae. A, B, F, G, Candy 47: C, D, Hoist 362: E, S.M. Perold 2976: H-K, M. N,

Bottomley CH175: L, Burtt Davy 15176. Scale bars: A-C, E, 1 mm; D, 100 pm; F-H, 50 pm; I-N, 250 pm. Drawings by

G. Condy.

38

HEPATOPHYTA: Aytoniaceae

HEPATOPHYTA: Aytoniaceae

39

to wine red, body ± 950 pm long, margins occa-

sionally with projecting papillae, base arched, ±

1650 pm wide, narrowed above and slightly

constricted or pleated where joined with 1 or 2,

sometimes 3 tapering appendages, 650-900 pm

long, basally 250-350(-400) pm wide, apex not

acuminate but often unicellular, ± 14 smaller oil

cells scattered throughout scale.

Dorsal epidermal cells unistratose, hyaline,

polygonal, 25-40 x 20-35 pm, walls with

trigones at corners, smooth externally; air pores

slightly raised, simple, 12.5-27.5 pm wide, sur-

rounded by innermost ring of small, collapsed

cells, then by 3 concentric rings of 7 or 8 larger

cells in each, radial walls sometimes thickened.

Assimilation tissue 375-475 pm thick, air

chambers empty, in several storeys, bounding

walls chlorophyllose; storage tissue well devel-

oped; oil cells scattered throughout tissues.

Monoicous, but male and female receptacles

sometimes on separate plants. Androecia medi-

anly at base of smaller, articulate, apical inno-

vation of leading branch, sessile cushions, kid-

ney- or sausage-shaped, basally encircled by

apically tapered, dark red paleae, 250-500 x

(90—) 1 00— 1 20 pm, margins sometimes with

projecting papillae. Gynoecial receptacles

medianly near apex of branch, single or occa-

sionally paired when branches bifurcate,

enclosed by arching, hyaline, tapering paleae, ±

550 x 80 pm, margins sometimes with papillae;

carpocephala 3.25 x 3.25 mm, when 4 lobes

present. Stalk 3— 6(— 9) mm long, ± 850 pm

wide, striate and dark red. Involucre bilabiate.

Figure 7. Spores 82.5-90.0 pm diam., triangu-

lar-globular, polar, brown, translucent; wing up

to 12.5 pm wide, porate at corners, margins

undulate, finely crenulate; ornamentation simi-

lar on two faces; distal face with 4 or 5 alveoli

across, 22.5-32.5 pm wide, walls wide and

finely granular; proximal face with distinct tri-

radiate mark, arms ± 5 pm high, mostly 4 shal-

low alveoli on each of 3 facets, walls sparsely

sprinkled with granules. Elaters light brown,

175-225 pm long, 15-20 pm wide in middle,

tapering toward ends, 5. 0-7. 5 pm wide, laxly

bispiral or spirals interrupted. Chromosome

number, n = 9 (Bischler 1978). Plate 3A-C.

The species is widespread in Africa and has

been reported by Bischler (1978) from Sierra

Leone, Guinea, Cameroons, Zaire, Djibouti,

Ethiopia, Uganda, Kenya, Tanzania, Malawi

and the following islands: Cape Verde, Reunion

and Madagascar (Bischler 1990). Its distribu-

tion extends to the Arabian Peninsula: Saudi

Arabia, Yemen, Oman and to Socotra.

Several of the southern Africa collections are

from high altitudes, such as the Drakensberg in

KwaZulu-Natal and Lesotho, where the plants

grow in shady kloofs, on muddy rock faces or on

soil covering rocks or under boulders. Map 3.

Plagiochasma eximium is a rather variable

species, but can be distinguished by its robust,

yellow-green thalli with large, deep pink to

wine-red ventral scales narrowed above into

(1)2 or 3 tapering appendages which are only a

little constricted or pleated at the base. Ventrally

the flanks are wrinkled and deep red, not dark

purple. Elaters from the few spore-bearing

plants studied are bispiral, but Bischler (1978)

also found them to be tri- or quadrispiral and

spirals generally distinct along only a small part

of their length.

Vouchers: H. Anderson CH4500; Esterhuys-

en 26166 (BOL); Perold 2498; Sim CH1186;

Volk 84/650 p.p.

5. Plagiochasma beccarianum Steph. in

Bulletin de l’Herbier Boissier 6: 781 (1898);

Bischl.: 257 (1978); O.H.Volk: 240 (1979);

Perold: 27 (1995a). Type: Abyssinia (Bogos),

Figure 7. — Plagiochasma eximium. A-C, E, thallus: A, with 2 carpocephala; B, with androecium; C, ventral face; E,

cross section. D, c/s of stalk. F, G, air pore; F, c/s dorsal cells and air chambers; G, dorsal cells from above. H, margin of

thallus. I-K, scales; I, with 1 appendage; J, with 2 appendages; K, appendage. L, M, male paleae; N, female paleae. A-C,

L, S.M. Perold 2498; D-I, Sim CH1I63; J, K, H. Anderson CH4498; M, Sim CH1200. Scale bars: A-C, 2 mm; D, 100 pm;

E, 1 mm; F-H, 50 pm; I-N, 250 pm. Drawings by G. Condy.

40

HEPATOPHYTA: Aytoniaceae

Plate 3 — Spores and elaters. A-C, Plagiochasma eximium: A, distal face; B, proximal face; C, elater. D-F, P. bec-

carianum D, elater; E, distal face; F, proximal face. A, C, Sim 9076\ B, Sim CH1163\ D-F, Volk 00950 A x 630’ B

E, x 600; C, x 400; D, x 500; F, x 580.

HEPATOPHYTA: AYTONIACEAE

41

Keren, in Monte Deban, inter 4500' & 5500',

1870, Beccari (FI, holo.; G009583, iso.!).

Thalli medium-sized to rather large, in gre-

garious patches; bright green and shiny, finely

and irregularly areolate, air pores distinctly vis-

ible, margins narrowly purple, sparsely scal-

loped and slightly undulate; when dry, margins

tightly inflexed. Branches once or twice pseu-

dodichotomously furcate, sometimes articulate

with apical innovations, ligulate to lingulate,

8-20 mm long, 3.5-5.0(-6.0) mm wide,

600-850 pm thick medianly, in section 6-8

times wider than thick, apex notched with sev-

eral purple, ovate-lanceolate scale appendages

recurved over edge; groove absent, thallus dor-

sally flat, margins acute, thin; flanks sloping

obliquely; ventral face medianly keeled, green.

Scales in 2 ventral rows, asymmetric, obliquely

triangular, deep purple to violet, body ± 850 pm

long, margins sometimes with a few prominent,

1-3-celled teeth, base flatly arched, ± 1750 pm

wide, gradually tapered above into 2 or 3 lance-

olate appendages, up to 1000 pm long, not con-

stricted at base, ± 400 pm wide, margins also

occasionally toothed, ± 10 small oil cells scat-

tered throughout scale.

Dorsal epidermal cells unistratose, hyaline,

polygonal, 25.0-37.5 x 20.0-27.5 pm, walls

thin, at comers with trigones; air pores slightly

raised, simple, 15-30 pm wide, surrounded by

innermost ring of small, collapsed cells, then by

2 (or 3 partly) concentric rings of 6-8 larger cells

in each, radial walls not thickened. Assimilation

tissue 300-400 pm thick, air chambers empty, in

several storeys, bounding walls chlorophyllose;

storage tissue occupying ventral part of thallus;

oil cells scattered throughout tissues.

Monoicous, but receptacles often on separate

plants. Androecia medianly and generally just

proximal to apical innovation, sessile cushions,

kidney-shaped or rounded, basally surrounded

by purple paleae, 300-400 x 160-200 pm, api-

cally pointed or blunt, margins sometimes with

projecting papillae. Gynoecial receptacles medi-

anly near apex of main branch or on apical inno-

vation, single, sometimes 2 in acropetal se-

quence, basally surrounded by dark paleae with

pointed apex, up to 500 x 80 pm, sometimes a

few papillae at margins; carpocephala up to 3.5 x

3.5 mm, when 4 lobes present. Stalk 1.2-3. 5 mm

long, ± 825 pm wide. Involucre bilabiate. Figure

8. Spores 80-90 pm diam., triangular-globular,

polar, light brown; wing 10 pm wide, porate at

corners, margin finely crenulate; ornamentation

similar on 2 faces; distal face with 3 or 4 alveoli

across, 20-25 pm wide, walls ± 7.5 pm wide and

finely granular; proximal face with distinct trira-

diate mark, ridge ± 7.5 pm high, each of 3 facets

with 4 alveoli, walls wide and sprinkled with

granules. Elaters light brown, 195-258 pm long,

12.5 pm wide in middle, tapering toward ends,

7.5 pm wide, occasionally branched, bispiral

except at tips. Chromosome number, n = 9

(Bischler 1978). Plate 3D-F.

The species is rare and has been reported

from relatively few places in Africa; except for

Namibia {Volk 00950), it is mostly found along

the eastern part of the continent, namely

Ethiopia, Tanzania and Zambia (Bischler 1978).

It has also been reported from the Arabian

Peninsula (Frey & Kiirschner 1988) and from

Socotra (Bischler 1978; Frey & Kiirschner

1988). Some specimens from Northern Pro-

vince and Mpumalanga have recently been col-

lected, where they grew in a shady kloof under

boulders or in a rocky crevice in Blyde River

Canyon respectively. Map 3.

Plagiochasma beccarianum is regarded as

quite a heterogeneous species, but so closely

resembling P. eximium that the two species are

often difficult to distinguish when sterile

(Bischler 1978). In the few southern African

specimens of P beccarianum available for

study, it appears that the fresh thalli are a clear

green dorsally, not yellow green, and the under-

side of the wings as well as the scales are deep

purple and not dark red as in P. eximium. The

two or three scale appendages of P. beccari-

anum are ± acuminate or narrowly triangular

and not constricted at the base; their margins are

irregularly toothed.

Bischler (1978) states that P. beccarianum

belongs to a complex represented by several

species in Asia and America. She thinks that

42

HEPATOPHYTA: Aytoniaceae

M

HEPATOPHYTA: AYTONIACEAE

43

this group probably diversified more rapidly on

these two continents than in Africa and that the

heterogeneity of P. beccarianum could be due

to a slower African evolution of the complex'

which has not as yet achieved separation into

distinct taxonomic units.

Vouchers: Glen 1250; Perold 2992, 2995; Volk

00950 (BOL).

Subfamily REBOULIOIDEAE

Reboulioideae Grolle in Feddes Repertorium 87: 244 (1976). Type: Reboulia Raddi.

Thalli smallish to large, in loose or crowded patches or in dense mats; lime green to bright green,

sometimes becoming reddish or bronzed. Branches simple or rarely once/twice pseudodichoto-

mously furcate, or with ventrolateral or apical innovations, apex slightly notched or entire; groove

mostly absent, thallus dorsally flat to slightly concave, margins thin, somewhat scalloped or irregu-

larly crenate, hyaline or purple or black; flanks sloping obliquely to very obliquely, often deep pur-

ple or black and shiny, sometimes transversely wrinkled; ventral face medianly keeled. Scales ven-

tral, smallish to large, in 2 rows, one on either side of keel, body obliquely triangular or semilunate,

hyaline or reddish pink to dark red or purple or black to reddish black, apically with lanceolate, ovate

or filiform appendages, scattered oil cells present throughout.

Dorsal epidermis mostly lacking chloroplasts, cells thin- or thick-walled, trigones present or

absent; air pores simple, rarely stellate, slightly raised, surrounded by 3 concentric rings of cells.

Assimilation tissue with air chambers very rarely containing a few chlorophyllose filaments, most-

ly empty and in storeys, rarely in 1 layer and then tall; storage tissue with closely packed

parenchymatous cells.

Monoicous, paroicous or autoicous, rarely dioicous. Androecia sessile, well defined or not,

antheridia sunken in disc or clustered or in 1 or 2 rows on main or ventrolateral branch. Gynoecial

receptacle on stalk emerging from apical notch or at bifurcation of branches or rarely ventrolater-

al; carpocephalum with top almost smooth or with prominent papillae, domed to low conical, or

umbonate, or disciform-round, not or scarcely lobed beneath. Stalk elongate, with 1 rhizoid furrow,

sometimes with air chambers. Involucres membranous, bell-shaped or bilabiate. Pseudoperianth

only present in Asterella spp. Sporophyte with short seta, capsule globose, wall thickenings rarely

present, dehiscing along well-defined line. Spores triangular-globular, winged, both faces alveo-

late, with thick or thin walls and then with subsidiary alveoli or with swollen bullae. Elaters taper-

ing, bi- or trispiral. Chromosome number: n = 9 or multiples thereof, or 10.

The genera Asterella , Mannia, Cryptomitrium and Reboulia are classified in the subfamily

Reboulioideae. The presence of Reboulia in southern Africa has not been confirmed.

ASTERELLA

Asterella P.Beauv. in Dictionnaire des sciences naturelles 3: 257 (1805); A.Evans: 247 (1920);

Frye & L. Clark: 69 (1937); Hassel de Menendez: 100 (1963); S.W.Arnell: 59 (1963a); Vanden

Figure 8. — Plagiochasma beccarianum. A-C, E, thallus: A, with mature carpocephalum; B, with archegoniophore and

androecium; C, ventral face; E, cross section. D, c/s of stalk. F, G, air pore; F, c/s dorsal cells and air chambers; G, from

above. H, margin of thallus. I-K, scales; I, with 2 appendages; J, with 3 appendages; K, appendage. L, male paleae; M,

female paleae. A, B, D-K, M, Volk 00950 ; C, S.M. Perold 2992 ; L, S.M. Perold 2995. Scale bars: A-C, 2 mm; D, 100 pm;

E, 1 mm; F-H, 50 pm; I-M, 250 pm. Drawings by G. Condy.

44

HEPATOPHYTA: AYTONIACEAE

Berghen: 169 (1972); R.M.Schust.: 224 (1992c); Perold: 133 (1994c). Type: A. tenella (L.)

P.Beauv. (= Marchantia tenella L.; lecto., designated by Long & Grolle 1992).

Fimbraria Nees: 44 (1820); Gottsche et al.: 555 ( 1844-1847); Schiffn.: 33 (1893); Steph.: 84(1899); Sim: 22 (1926);

Miill.Frib.: 353 (1951-1958) nom. illegit. Lectotype: F. marginatu Nees.

Hypenantron Corda: 648 (1829). Type: H. ciliatum Corda.

Dictyochiton Corda ex Nees: 258 (1838) non rite publ.

Rhacotheca Bisch.: 12 (1844). Type: R. azorica Bisch.

Octokepos Griff.: 343 (1849). Type: O. khasyanum Griff.

Thalli medium-sized to fairly large, in crowded patches or dense mats; lime green to bright green,

firm or rarely somewhat spongy. Branches simple, rarely once or twice pseudodichotomously fur-

cate, or with ventrolateral or apical innovations, ligulate, obovate or obcordate, apex slightly notched,

with tips of ventral scales recurved over edge; groove absent, rarely present at apex only, otherwise

thallus dorsally flat, margins thin, somewhat scalloped, attenuate, frequently purple; flanks sloping

obliquely, purple or black or green; ventral face medianly keeled. Scales ventral, in 2 rows, one on

either side of keel, body ovate to obliquely triangular, mostly purple or wine-red, apically with 1,

rarely 2 or 3 lanceolate or ovate appendage(s), margins mostly entire, scattered oil cells present

throughout.

Dorsal epidermis mostly without chloroplasts, cells thin-walled, lacking trigones; air pores

small, simple, slightly raised, surrounded by 2 or 3 concentric rings of 6-8 cells in each, radial

walls of cells rarely thickened, pores then stellate. Assimilation tissue with small, empty air cham-

bers in several irregular, low storeys, or in single tall storey, cells in bounding walls chlorophyl-

lose; storage tissue with rounded or angular cells, closely packed together.

Monoicous, paroicous, or autoicous, rarely dioicous. Androecia with antheridia in paroicous

species in a vaguely defined cluster or a row immediately or somewhat more proximal to foot of

archegoniophore stalk; in autoicous or dioicous species, androecia well-defined, on reduced ven-

trolateral branches or as median oval disc on main branch. Gynoecial receptacle raised on stalk,

emerging from apical notch of main or ventrolateral branch, base encircled by paleae; car-

pocephalum rounded or umbonate, nearly smooth to distinctly papillose, air chambers opening via

compound pores, below with ( 1— )2— 4(— 5) lobes. Stalk elongate, with one rhizoid furrow, with or

without air chambers, at summit with paleae, rarely without. Involucres membranous, continuous

with edges of lobes. Pseudoperianths present, mostly pendulous, conical or blunt, vertically split

into segments, connate at tips, covering and projecting beyond capsules in all but one southern

African species. Sporophyte with very short seta, capsule globose, wall lacking thickening bands,

dehiscing by well-defined lid. Spores triangular-globular, winged, both faces with regular or irreg-

ular network of large, angular to rounded alveoli, bordered by ridges and generally lined with small

subsidiary alveoli; proximal face also with pronounced triradiate mark. Elaters short or of medium

length, uni- to trispiral. Chromosome number, n = 9 or multiple thereof, or 10.

Asterella is one of the larger genera of the Marchantiales and occurs world-wide. It has been

divided into three subgcnera: Brachyblepharis, Asterella and Phragmoblepharis, the latter with

three sections, namely Pappiae, Lindenbergianae and Saccatae (Grolle 1976). Four of the south-

ern African species of Asterella are placed in subgenus Phragmoblepharis Grolle, since the seg-

ments of the pseudoperianths remain connate at their tips for a long time, in contrast to those in

subgenera Brachyblepharis and Asterella, where they separate at maturity; only A. abyssinica is

placed in subgenus Brachyblepharis.

Asterella species are easily recognized when fertile, by the presence of the basket-like

pseudoperianth, which soon splits into narrow segments.

HEPATOPHYTA: AYTONIACEAE

45

Key to the southern African species of Asterella

la Pseudoperianth with segments apically free at maturity . . . subgenus Brachyblepharis:

1. A. abyssinica

lb Pseudoperianth with segments remaining apically connate at maturity . . . subgenus

Phragmoblepharis:

2a Thalli spongy, with tall air chambers mostly in one storey, and then not subdivided by

supplementary partitions, each opening dorsally by a stellate pore; ventral scales

occasionally fimbriate at single lanceolate appendage; carpocephalum round or

umbonate and lacking paleae at summit of stalk; pseudoperianth extending + 300 pm

beyond involucre and subdivided into 12 or 13 segments; spores 75-95 pm diam.,

dark brown, ornamentation with irregular zig-zagging ridges 2. A. muscicola

2b Thalli compact, firm, with small, low air chambers in several storeys, only some top

ones opening above by a dorsal, non-stellate pore; ventral scales with 1 (or 2) lance-

olate or ovate appendages, margin ± entire; carpocephalum round or umbonate, papil-

lose or ± smooth, with paleae at summit of stalk; pseudoperianth extending more than

1000 pm beyond involucre and subdivided into 14-16 segments; spores more than

100 pm diam., yellow or brown, ornamentation with larger alveoli generally con-

taining subsidiary alveoli:

3a Thalli smallish to large; carpocephalum covered with distinct papillae, projecting +

200 pm; paleae at summit of stalk shaggy, dense, pale mauve or colourless, up to

3000 pm long and 4 or 5 cells wide at base; ventral scales with lanceolate

appendage; spores elaborately ornamented with 6-8 alveoli across distal face,

20-30 pm wide and ridges extending across wing, containing numerous subsidiary

alveoli (common, mostly summer rainfall species) 3. A. bachmannii

3b Thalli medium-sized to very large; carpocephalum ± smooth or with low papillae;

paleae at summit of stalk colourless or purple, length variable; ventral scales with

lanceolate or ovate appendages; spores less elaborately ornamented:

4a Thalli medium-sized; carpocephalum with umbonate head; paleae at summit of stalk

mostly colourless, some very long, more than 8000 pm in length, + 4 cells wide

at base; ventral scales with 1 or 2 lanceolate appendages; spores on distal face with

(4— )6— 9 alveoli across, ± 32 pm wide, very high ridges seldom extending across

wing, usually containing small subsidiary alveoli (winter rainfall species)

A. A. marginata

4b Thalli large to very large; carpocephalum with rounded head, distinctly lobed below;

paleae at summit of stalk almost colourless to purple, 2000-3000 pm long, some

up to 7 cells wide at base; ventral scales with single, large-celled, ovate append-

age, constricted at base; spores on distal face with 5-8 alveoli across, 25-30 pm

wide and extending to wing margin, almost empty of subsidiary alveoli and hollow

(summer rainfall, mostly Afromontane species) 5. A. wilmsii

1. Asterella abyssinica ( Gottsche ) Grolle

in Vanden Berghen: 170 (1972).

Fimbriaria abyssinica Gottsche in Gottsche et al.: 569

(1844-1847); Hypenantran abyssinicum (Gottsche) Trevis.:

441 (1877); Steph.: 109 (1899). Type: Abyssinia cum

Targionia elongate, in caespite Un. itin. n. 500 a Kotschy

lecto (not seen).

Thalli smallish to medium-sized, in crowded

mats; green to light olive-green, hardly areolate,

air pores not visible, margins hyaline or tinged

with mauve to deep purple, weakly scalloped,

slightly undulate; when dry, thallus margins flat

or raised to partly indexed. Branches simple or

once pseudodichotomously furcate, with apical

46

HEPATOPHYTA: Aytoniaceae

HEPATOPHYTA: Aytoniaceae

47

or ventrolateral innovations, widening gradual-

ly from a stipitate base, 15-18 mm long,

2.3-5. 0 mm wide, 400-450 (-630) pm thick

medianly, in section 6-11 times wider than

thick, apex slightly notched, tips of few ventral

scales recurved over edge; groove absent, thal-

lus dorsally flat, margins acute, thin; flanks

sloping obliquely, entirely or only distally pur-

ple; ventral face medianly keeled, green. Scales

in 2 ventral rows, obliquely triangular, in differ-

ent shades of mauve to purple, body up to 800

pm long, margins ± entire, base occasionally

crescentic, 650-750 pm wide, narrowed above

and sometimes constricted where joined to sin-

gle oblong or elliptical appendage, 420-430 pm

long, + 200 pm wide basally, tapering above to

conical apical cell, up to 12 small, colourless oil

cells scattered throughout scale.

Dorsal epidermal cells unistratose, contain-

ing chloroplasts, thin-walled, 5- or 6-sided,

(40.0-)45.0-65.0(-72.5) x 22.5-37.5 pm; air

pores hardly raised, simple, + 12.5 x 10.0 pm,

surrounded by innermost ring of small col-

lapsed cells, then by 2 concentric rings of 6 or 7

larger cells in each, radial walls not thickened.

Assimilation tissue 215-260 pm thick, air

chambers small, empty, in 2 or 3 storeys,

bounding walls chlorophyllose; storage tissue

confined to keel, cells closely packed together;

oil cells scattered throughout tissues.

Autoicous. Androecia in sessile, thickened

cushions, elongated or oval, occasionally fur-

cate, near apex of branch or more proximally at

constriction, opening above into conical papil-

lae. Gynoecial receptacles proximal to apical

notch of main branch or just proximal to stipi-

tate innovation of apical branch, single, occa-

sionally paired at apices of 2 furcate branches,

± sessile when young, later raised on stalk; car-

pocephalum rather flat to weakly convex, sub-

orbicular, 3. 5-4.0 mm across, above almost

smooth. Stalk arising ± 1.7 mm proximal to

Map 4. — ■ Asterella abyssinica

• Asterella muscicola

▲ A. marginata

□ A. wilmsii

apex of branch in apical notch, 4-5 mm long,

whitish green or streaked with purple, widening

slightly toward base, at midlength ± 520 pm

wide, with rhizoid furrow, at summit of stalk

and scattered along its length, colourless or pur-

ple paleae, up to 820 pm long, 2 or 3 cells wide

basally, above 3-5 cells wide, tapering to apical

cell. Involucre membranous, partly covering

capsules below. Pseudoperianths extending up

to 1250 pm beyond involucre, generally with

8-10 white segments, tapering to narrow tips

that become free before capsule dehiscence.

Sporophyte with obovoid capsule, thin-walled

and lacking thickening bands. Figure 9.

Spores 62.5-72.5 pm diam., triangular-glob-

ular, pale yellow to yellow, translucent; wing

undulate, up to 10 pm wide, margin crenulate;

distal face convex, reticulate, with network of ±

6 larger, primary alveoli across, ± 10-15 pm

wide and extending over wing, their delimiting

ridges only slightly raised and not clearly

defined among the numerous walls of small,

subsidiary alveoli, alveolar floor highly porate;

proximal face with prominent triradiate ridge,

Figure 9. — Asterella abyssinica. A, B, E, thallus: A, dorsal view with gametoecia on separate branches of same plant;

B, ventral view; E, cross section. C, carpocephalum raised on stalk; D, ventral view of carpocephalum. F, G, air pore: F,

c/s with air chamber; G, from above. H, marginal cells of thallus; I, ventral scale; J, c/s of stalk; K, paleae. A-J, Duckett

& Matcham 6049 ; K, S.M. Perold 2674. Scale bars: A-E, 1 mm; F-H, 50 pm; I, J, 250 pm; K, 100 pm. Drawings by G.

Condy.

48

HEPATOPHYTA: Aytoniaceae

Plate 4. — Spores of Asterella abyssinica, Duckett & Matcham 6049. A, distal face; B, proximal face. A, x 745; B, x 710.

its arms continuous from pole to wing, but not

clearly extending across, each of 3 facets with

numerous alveoli, larger at pole and smaller

toward wing, but not clearly arranged in prima-

ry and subsidiary alveoli, floor also highly

porate. Plate 4A, B. Elaters 135-150 pm long,

10 pm wide in centre, slightly tapering toward

rounded ends, bispiral. Chromosome number.

unknown.

The species has only very recently been

collected in the Flora area, namely in Kwa-

Zulu-Natal. Map 4. The range of A. abyssinica

extends northwards into Zimbabwe, Malawi

(Perold 1997), Tanzania, Rwanda, Burundi, Ethio-

pia, Zaire, Cameroun and Sierra Leone (Wig-

ginton et al. 1996). It frequently grows at high

altitudes on streambanks or on damp rocks in

association with other liverworts such as Tar-

gionia hypophylla and Asterella bachmannii.

It is easily recognized by the rather flattened

round discs of the carpocephala, by horizontal-

ly protruding pseudoperianths, their rather short

segments becoming free at the tips before the

capsules dehisce.

Voucher: Duckett & Matcham 6049.

2. Asterella muscicola (Steph.) S.W.Amell,

Hepaticae of South Africa: 60 (1963a); Perold:

135 (1994c).

Fimbraria muscicola Steph.: 121 (1892); Steph.: 97

(1899); Sim: 22 (1926). Type: Mpumalanga [Transvaal],

Spitzkop bei Lydenburg, Febr. 1888, leg. Wilms G001664,

holo.! (G); G024589. iso.! (G).

Thalli medium-sized to fairly large, in crowd-

ed patches; bright green, areolate, somewhat

spongy, air pores tiny, white specks, very slight-

ly raised, margins soon turning purple, becom-

ing wider proximally and pinkish purple, scal-

loped and undulate, in older parts dead; when

dry, thallus margins tightly clasped together.

Branches simple or once/twice pseudodichoto-

mously furcate, oblong, up to 18 mm long,

2.5-3.5(-6.5) mm wide, ± 1250 pm thick medi-

anly, in section 2-5 times wider than thick, apex

notched, tips of ventral scales recurved over

edge; groove faintly present toward apex, thallus

dorsally concave more proximally, margins

acute, thin; flanks sloping obliquely; ventral

face medianly keeled, green. Scales in 2 ventral

rows, obliquely triangular, wine red to deep pur-

ple, body 700-800 pm long, margins sometimes

with several 1- or 2-celled papillae, base curved,

1 100-1250 pm wide, narrowed above to acumi-

nate appendage, 170-350 pm long, apex tapered

and occasionally fimbriate, 2-8 small, colour-

less oil cells scattered throughout scale.

Dorsal epidermal cells unistratose, hyaline,

thin-walled, without trigones, 4- or 5-(-7)-sided,

(37.5-)45.0-72.5 x 15.0-25.0 pm; air pores very

HEPATOPHYTA: AYTONIACEAE

49

slightly raised, simple, ± 7.5 pm wide, surround-

ed by innermost ring of small collapsed cells,

then by 2 concentric rings of 6 larger cells in

each, radial walls mostly thickened and pores

stellate. Assimilaton tissue ± 650 pm thick, air

chambers tall and empty, mostly in one storey,

bounded by chlorophyllose, unistratose walls;

storage tissue with cells tightly packed together;

oil cells scattered throughout tissues.

Paroicous. Androecia with antheridia group-

ed or in 1 or 2 short rows along midline of thal-

lus, generally immediately proximal to stalk,

very rarely on separate plant, immersed, open-

ing above into prominent, conical papillae.

Gynoecial receptacles single, rarely paired at

apices of 2 furcate branches, almost sessile

when young, later raised on stalk; carpo-

cephalum rounded to somewhat umbonate, ± 3

mm across, air pores compound, below with 3-5

capsules (sometimes 2 together in same involu-

cre). Stalk arising at bifurcation of branches, the

latter continuing in growth, yellowish, shiny,

ribbed, stout, erect or somewhat bent, 5-8 mm

long, ± 675 pm wide at midlength, becoming

thicker toward base and tapering toward naked

summit, with one rhizoid furrow and narrow to

wide air chambers. Involucre ± bilabiate, enclos-

ing base of pseudoperianth and capsule.

Pseudoperianths extending obliquely down-

ward, projecting ± 300 pm beyond involucre,

somewhat flattened sideways, with 12 or 13

cage-like, hyaline segments, connate at tips.

Sporophyte with swollen foot and very short

seta, capsule globose, ± 875 pm diam., wall

unistratose, lacking thickening bands. Figure 10.

Spores 75-95 pm diam., triangular-globular,

dark brown, opaque; wing somewhat pleated, 5

pm wide, margin undulate; distal face convex,

reticulate, with very irregular, mostly incom-

plete alveoli, ridges forming an irregular, zig-

zagging maze; proximal face with distinct trira-

diate mark, facets also with irregular, incom-

plete alveoli, ranging from small and crowded to

larger and more widely dispersed. Elate rs

150-175 pm long, 17.5 pm wide in centre,

slightly tapering toward ends, bispiral, light

brown. Chromosome number: n = 10 (T.

Bornefeld pers. comm.). Plate 5A, B.

The range of A. muscicola extends into

Malawi (Kasunga Nat. Park, Perold 2682) and

Zimbabwe ( Eyles 932, 933; Miller 7869) from

where it is also reported by Best (1990). The

species is probably endemic to southern Africa

and in the FSA area is known from Botswana,

Northern Province, North-West, Mpumalanga,

Free State, KwaZulu-Natal, Lesotho, and East-

ern Cape. Map 4.

It frequently grows at high altitudes on soil

overlying sandstone or basalt outcrops in asso-

ciation with other liverworts such as Plagio-

chasma spp. and Riccia spp.

Sterile specimens of A. muscicola have been

confused with Athalamia spathysii, since the

dorsal air pores of the thallus in both spp. are

stellate. In A. muscicola the air chambers are

devoid of chlorophyllose filaments, but oil bod-

ies are present and their remains are present in

the scales which have cells half as wide as those

of A. spathysii. It differs from Athalamia

species mainly in sporophyte characters: the

stalk arises at the bifurcation of the branches, it

is thicker and has a rhizoid furrow, it is also

devoid of scales both at the base and summit;

the cells in the capsule wall lack annular or

semi-annular thickenings; pseudoperianths are

present; the spores are larger, dark brown and

winged, their ornamentation is reticulate (not

papillose); the elaters are shorter and wider.

Vouchers: H. Anderson 1248; Marais 832;

Mott 861; Perold & Koekemoer 2968; Smook

8237.

3. Asterella bachmannii (Steph.) S.W. Ar-

nell, Hepaticae of South Africa: 62 (1963a);

Perold: 137 (1994c). Type: Pondoland, Port Gros-

venor, Bachmann ( G13866 , lecto.!; G1 38671).

Fimbraria bachmannii Steph : 7 (1894); Steph.: 105

(1899); Sim: 22 (1926).

Thalli smallish to quite large, in crowded

mats; light green, rather crystalline to shiny,

firm and compact, faintly areolate or not, air

pores tiny, scattered, margins turning purple,

slightly scalloped, somewhat undulate; when

HEPATOPHYTA: AYTONIACEAE

51

dry, thallus margins raised or indexed, some-

times inrolled. Branches simple or occasionally

once, rarely several times pseudodichotomous-

ly furcate, often with apical or ventrolateral

innovations, broadly ligulate, widening rapidly

from narrow base, 1 8-25 mm long, (1 ,9-)2.5-4.0

(-4.9) mm wide, (450-) 500-600 (-775) pm

thick medianly, in section 5 or 6 times wider

than thick, apex notched, tips of ventral scales

recurved over edge; groove absent, thallus dor-

sally flat, margins acute, thin; flanks sloping

obliquely, red to deep purple; ventral face medi-

anly keeled, green. Scales in 2 ventral rows,

obliquely triangular, red to deep purple, body

up to 1000 pm long, margins ± entire, base cres-

centic, ± 1500 pm wide, narrowed above and

constricted where joined to single lanceolate

appendage, occasionally 2, 450-650 (-800) pm

long, 150-200 pm wide basally, tapering above

to conical apical cell, ± 8 or more small, colour-

less oil cells scattered throughout scale.

Dorsal epidermal cells unistratose, generally

containing chloroplasts, thin-walled, (4-)5- or

6-sided, (30.0)-50.0-67.5(-90.0) x 22.5-30.0

pm; air pores slightly raised, simple, ± 17.5 x

12.5 pm, surrounded by innermost ring of small

collapsed cells, then by 2 concentric rings of

6— 8(— 1 0) larger cells in each, radial walls not

thickened. Assimilation tissue up to 280 pm

thick, air chambers small, empty, in 2-4

storeys, bounding walls chlorophyllose; storage

tissue mostly confined to keel, cells closely

packed together, walls thick and pitted; oil cells

scattered throughout tissues.

?Dioicous, rarely autoicous. Androecia

naked, sessile, elongated or oval cushions,

medianly near apex of main branch, rarely also

at ± midlength constriction, sometimes on short

apical or lateral innovations, antheridia

immersed, opening above into stout, raised,

purple-red papillae. Gynoecial receptacles

proximal to apical notch of main branch or

rarely on short ventrolateral innovations, single,

occasionally paired at apices of 2 furcate

branches, almost sessile when young, with

numerous (± 75), long, pale, sometimes purple

paleae arching over disc, at maturity raised on

stalk; carpocephalum rounded, ± 3 mm across

when bearing 4 or 5 capsules, frequently with

only 1 or 2 and then smaller, above with numer-

ous prominent papillae, containing air cham-

bers which open via compound air pores. Stalk

arising 1.5 mm proximal to apex of branch in

apical notch, length variable, ( 1— )5— 1 3(— 20)

mm long, at midlength ± 550 pm wide, widen-

ing toward base, whitish to purple, with single

rhizoid furrow, at summit ± 32 slender, shaggy

paleae, white or purple, up to 3250 pm long, 4

or 5 cells wide at base, gradually tapering to

conical apical cell. Involucre membranous,

partly covering capsule below. Pseudoperianths

descending obliquely downward and extending

± 1000 pm beyond involucre, generally split

into 14 cage-like segments, shiny white or pur-

ple-stained, tapering to narrow, connate tips.

Sporophyte with globose capsule, ± 1000 pm

diam., wall unistratose, lacking thickening

bands, dehiscing along well-defined line.

Figure 11. Spores 102.5-125.0 pm diam., trian-

gular-globular, mostly yellow, sometimes

brown, translucent; wing undulate, up to ± 20

pm wide, margin crenulate; distal face convex,

with network of 6-8 angular alveoli across,

20-30 pm wide, ridges 7.5-10.0 pm high and

laterally extending across wing, floor of alveoli

highly porate and generally with smaller sub-

sidiary alveoli, these also extending over crests

of main ridges; proximal face with prominent

triradiate ridge, its arms ± 15 pm high, continu-

ous from pole and across wing to margin, each

of 3 facets with alveoli, ± 10 pm wide, also

extending across wing and containing many or

few, smaller, subsidiary alveoli that cross over

crests of main alveoli and onto wing to margin.

Figure 10. — Asterella muscicola: A, B, D, thallus: A, dorsal face; B, ventral face; D, cross section. C, carpocephalum

raised on stalk and antheridia proximal to foot of stalk. E, F, scales: E, with fimbriate apex; F, with acuminate apex. G, H,

air pore: G, c/s with air chamber; H, cells and oil cell from above. 1, c/s of stalk; J, 1/s of young archegoniophore; K, cap-

sule wall cells. A-C, E, G, I, J, Perold & Koekemoer 2968 ; D, F, H, Candy 13\ K, H. Anderson 1248. Scale bars: A-D, 2

mm; E, F, I, 250 pm; J, 1 mm; G, H, K, 50 pm. Drawings by A. Pienaar.

52

HEPATOPHYTA: Aytoniaceae

Plate 5 — Spores. A. B, Asterella muscicola: A, distal face; B, proximal face. C, D, A. bachmannii: C, dis-

tal face; D, proximal face. E, F, A. marginata: E, distal face; F, proximal face. A, B, Perold & Koekemoer 2968',

C, Glen 2155', D, Perold & Koekemoer 291 7; E, S.M. Perold 2418, F, Arnell 505. A, B, x 640; C, x 520; D, x 530;

E, x 545; F, x 400.

HEPATOPHYTA: Aytoniaceae

53

which is finely ornamented on both faces.

Elaters 142-165 (-180) |jm long, 15 |jm wide

in centre, slightly tapering to ends, bispiral, yel-

low. Chromosome number : n = 9 (T. Bornefeld

pers. comm.). Plate 5C, D.

The range of Asterella bachmannii extends

into Zimbabwe and Malawi (Nyika Nat. Park).

Best (1990) also reported it from Zimbabwe. It is

by far the most frequently collected Asterella

species in the summer rainfall areas of southern

Africa. It is known from Botswana, Northern

Province, Gauteng, Mpumalanga, Swaziland,

Free State, KwaZulu-Natal, Lesotho, Western

and Eastern Cape. Map 5. It is mostly found on

damp soil along stream banks, at waterfalls or in

shaded gulleys or kloofs, sometimes on soil-cov-

ered vertical rock walls, at seepages or on soil

overlying sandstone, in light shade or in full sun-

light. It occasionally grows together with A.

wilmsii, Symphyogyna species and Fossom-

bronia species.

Asterella bachmannii is a variable species and

can range in size from smallish to quite large.

The thallus margins and ventral face can be very

deeply pigmented or hardly at all, depending on

whether it is exposed to intense sunlight or not.

The ventral scales can likewise be deeply pig-

mented and the appendages are then not clearly

discernible against the purple flanks.

Fertile plants are easily recognized by the

mostly pronounced papillae covering the car-

pocephalum as well as by the dense, narrow,

stringy or shaggy paleae which are usually white,

but occasionally can be purple-stained. The

spores are highly ornamented with the main alve-

oli containing numerous smaller subsidiary alve-

oli on both faces, giving it a lacey appearance.

Sterile specimens can be distinguished from A.

muscicola by the compactness of the assimila-

tion dssue and from A. wilmsii, by its smaller size

and the lanceolate appendages (occasionally

double) of the purple or reddish purple ventral

scales and from A. marginata by its generally

purple, not wide, black thallus margins and by its

mostly summer rainfall distribution.

Vouchers: Glen 2150 ; Perold & Koekemoer

2856, 291 3\ Phelan 375.

4. Asterella marginata (Nees) S.W.Ar-

nell, Hepaticae of South Africa: 63 (1963a);

Perold: 140 (1994c). Type: Capite b. spei,

crescit iuxta viam in monte Leuwenstaart ad

terram, leg. Bergius s.n. (BM).

Fimbraria marginata Nees: 44 (1820); Gottsche et al.:

559 (1844-1847); Steph.: 104 (1899).

Thalli medium-sized, in crowded mats;

bright green, firm and compact, hardly areolate,

air pores slightly raised, scattered, margins with

narrow to wide black border, occasionally red-

dish purple, very wavy to almost frilly; when

dry, thallus margins raised to inrolled. Branches

simple or once, rarely twice pseudodichoto-

mously furcate, sometimes with apical or ven-

trolateral innovations, obovate to obcordate or

ligulate, frequently widening rapidly from nar-

row base, up to 23 mm long, 2. 3-5.0 mm wide,

550-565 pm thick medianly, in section 4—9

times wider than thick, apex notched, tips of

ventral scales recurved over edge; groove

absent, thallus dorsally flatfish to somewhat

concave, margins acute, thin; flanks sloping

obliquely, purple to black; ventral face median-

ly keeled. Scales in 2 ventral rows, obliquely

triangular, deep purple to lightly pigmented,

body ± 675 pm long, at margins few small

papillae, base crescentic, 825-925 pm wide,

narrowed above, not constricted where joined

to 1 or 2(3) lanceolate appendages, equally long

or not, length 675-925 pm, tapering above to

54

HEPATOPHYTA: AYTONIACEAE

HEPATOPHYTA: Aytoniaceae

55

single apical cell, basally ± 375 pm wide, up to

20 smaller oil cells scattered throughout scale.

Dorsal epidermal cells unistratose, mostly

hyaline, walls thin, slightly thickened at cor-

ners, 5- or 6-sided, 30.0-45.0 x 17.5-20.0 pm;

air pores slightly raised, simple, ± 10.0 x 7.5

pm, surrounded by innermost ring of small, col-

lapsed cells, and then by 2 concentric rings of

5-7 larger cells in each. Assimilation tissue

200-250 pm thick, air chambers small, empty,

in 2 or 3 storeys, bounding walls chlorophyl-

lose; storage tissue confined to keel, cell walls

porate, thickened, often with striate network of

bands; oil cells scattered throughout tissues.

Autoicous or monoicous. Androecia in ses-

sile cushions on ventrolateral innovations or at

base of main branches, antheridia immersed,

opening above into raised, purple papillae.

Gynoecial receptacles proximal to apical notch

of main branch, single, occasionally paired at

apices of 2 furcate branches, almost sessile

when young, at maturity raised on stalk; car-

pocephalum ± 3 mm across, umbonate, air pores

compound, slightly raised, sometimes quite con-

spicuous, ( 1— )3— 5(— 6) capsules borne below.

Stalk arising ± 1 mm proximal to branch apex in

notch, foot slightly wider than at midlength,

width ± 575 pm, with single rhizoid furrow,

length variable, 2.5-18.0 mm, white or reddish

purple, at summit (and along length) numerous

pale, occasionally purple paleae, some very

long, up to 8400 pm, others 1250-2750 pm,

base ± 100 pm or 4 cells wide, tapering to single

apical cell. Involucre membranous, partly cover-

ing capsule. Pseudoperianths descending oblique-

ly downward, extending ± 1100 pm beyond

involucre and divided into 15 segments, tapering

toward connate tips. Sporophyte with globose

capsule, ± 600 pm diam. Figure 12. Spores

( 1 02—) 1 25— 1 40 pm diam., triangular-globular,

yellow; wing undulate, 20 pm wide, margin

crenulate; distal face convex, centrally with

(4 — )6— 9 complete alveoli, ± 32.5 pm wide, outer

alveoli incomplete, ridges up to 12.5 pm high,

seldom extending across wing, smaller, sub-

sidiary alveoli, 2. 5-5.0 pm wide (and occasion-

ally even further divided up), generally covering

floor of larger alveoli and extending over crests

of main ridges; proximal face with prominent

triradiate mark, its arms 15 pm high and contin-

uous from pole across wing to margin, each of 3

facets with complete or mostly incomplete alve-

oli, main ridges sometimes extending across

wing, small subsidiary alveoli covering floor

and ridges of main alveoli, as well as arms of tri-

radiate mark. Elaters ± 145 pm long, 12.5 pm

wide in centre, slightly tapering to ends, bispiral,

yellow. Chromosome number: unknown. Plate

5E, F.

The distribution of A. marginata appears to

be confined to the mostly winter rainfall areas

of the Northern, Western and Eastern Cape.

Map 4.

Asterella marginata grows in dense mats on

clayey soil or on weathered, soil-covered rocks

at seepages or riverbanks, between rock crevices

and under ledges, sometimes in association

with Fossombronia spp., Bryum spp. and Riccia

spp.

Fertile specimens of A. marginata are easily

recognized by the umbonate head of the car-

pocephalum, which lacks prominent papillae;

the frequently very long, pale paleae, and the

spore ornamentation mostly with numerous

fine, ± regular, subsidiary alveoli contained

within the highly ridged, larger ones, which

usually do not extend across the wing. Sterile

collections of A. marginata are, however, dif-

ficult to place and have frequently been con-

fused with A. bachmannii ; in fact, Arnell (1963)

stated that he could find no real differences

between them, basing his opinion on their scale

Figure 11. — Asterella bachmannii. A, B, D, thallus: A, dorsal face; B, ventral face, appendages of scales mostly not

visible against dark purple flanks; D, cross section. C, carpocephalum with papillose disc and 2 pseudoperianths. E, F, air

pore: E, from above; F, c/s with air chamber. G, marginal cells; H, appendage and upper part of scale; 1, c/s of stalk; J,

paleae. A-D, I, Glen 2150 ; E, G, H, J, Perold & Koelcemoer 2856 ; F, Candy 7. Scale bars: A-D, 1 mm; E-G, 50 pm; H, I.

250 pm; J, 100 pm. Drawings by A. Pienaar.

HEPATOPHYTA: AYTONIACEAE

56

G

HEPATOPHYTA: AYTONIACEAE

57

appendages, air pores, epidermal cells and

spores.

Vouchers: Arnell 5359 (BOL); Bottomley

CH263; Dyer 863; Garside 6585; Koekemoer

869; Oliver 1474.

5. Asterella wilmsii (Steph.) S.W. Arnell,

Hepaticae of South Africa: 62 (1963a); Perold:

142 (1994c). Type: Spitzkopf bei Lydenburg,

Transvaal (Mpumalanga), leg. Dr Wilms (ex

Herb. Jack, G001666, lecto. fide Grolle in litt.).

Fimbraria wilmsii Steph.: 122 (1892); Steph.: 103

(1899); Sim: 23 (1926).

F. angolensis Steph.: 100 (1899); Asterella angolensis

S.W. Arnell: 64 (1963a). Type: Angola, Huilla, waterfall,

Newton 25a (G001673, holo.!).

Thalli large, in crowded, overlying mats;

yellowish green, not areolate, pores hardly

raised, margins dark red, gently scalloped,

somewhat undulate; when dry, thallus margins

slightly raised to inflexed. Branches simple or

once pseudodichotomously furcate, sometimes

with apical or ventrolateral innovations, broad-

ly ligulate, widening rapidly from narrow base,

30-40(-75) mm long, 4.7-7. 1 mm wide,

600-800(-950) pm thick medianly, in section 7

or 8 times wider than thick, apex notched, tips

of scale appendages recurved over edge; groove

absent, thallus dorsally flat to slightly concave,

margins acute, thin; flanks sloping obliquely,

reddish purple; ventral face medianly keeled,

green. Scales in 2 ventral rows, obliquely trian-

gular, purple-red, pink or hyaline, body

1000-1100 pm long, margin ± entire, base

950-1050 pm wide, continuing into long tail

below, narrowed above, constricted where

joined to large, ovate or roughly triangular

appendage, (850-) 1050-1200 pm long, apex

apiculate, width 420-500 pm across widest

part, cells distinctly larger than in base, ± 9 oil

cells scattered throughout scale.

Dorsal epidermal cells unistratose, contain-

ing chloroplasts, thin-walled, 5- or 6-sided,

50-95 x 25-35 pm; air pores very slightly

raised, simple, ± 17.5 x 8.0 pm, surrounded by

innermost ring of small, collapsed cells and

then by 2 concentric rings of (6— )7 — 9 larger

cells in each. Assimilation tissue (150-)

250-320 pm thick, air chambers small, empty,

in several storeys, bounding walls chlorophyl-

lose; storage tissue 450-650 pm thick over

keel, thinning out laterally, absent at margins,

cells angular, walls thick, porate and sometimes

with a network of striations; oil cells scattered

throughout tissues.

Autoicous. Androecia in sessile, thickened

cushions, oval or elongated or heart-shaped,

near apex of main branch, or of ventrolateral

innovation, antheridia immersed, opening above

into conspicuous papillae. Gynoecial recepta-

cles proximal to apical notch of main branch,

single, occasionally paired at apices of 2 furcate

branches, ± sessile when young, surrounded by

up to 70 purple paleae, not arching over disc, at

maturity raised on stalk; carpocephalum round-

ed, 3. 5-5.0 mm across when bearing 4 or 5 cap-

sules, sometimes with only 1 or 2, then smaller

and asymmetric, above almost smooth or with

low papillae further down. Stalk arising ± 2 mm

proximal to apex of branch in apical notch,

length variable, (2— )4 — 1 0(— 20) mm long, often

purple, widening toward base, at midlength ±

600 pm wide, with rhizoid furrow, at summit of

stalk (and protruding from notches in head),

dark purple paleae, occasionally pink or colour-

less, length variable, up to 2000 pm long, rarely

as much as 3250 pm long, but then narrower,

and only 3 cell rows wide, mostly up to 7 cell

rows or ± 325 pm wide at base, gradually taper-

ing to conical apical cell. Involucre membra-

nous, partly covering capsule below. Pseudo-

perianths extending up to 1500 pm beyond

involucre, generally with 16 segments, white or

Figure 12.— Asterella marginata. A, B, D, thallus: A, dorsal face with young carpocephalum raised on stalk and ses-

sile androecium; B, ventral face; D, cross section. C, carpocephalum and pseudoperianths. E, F, air pore: E, c/s with air

chamber; F, from above. G, marginal cells. H, I, scales: H, with 1 appendage; I, with 2 appendages. J, c/s of stalk; K, paleae.

A, B, D-F, H, I, S.M. Perold 2787', C, Pillans 3991; G, Arnell 505', J, Arnell 206; K, Koekemoer 316. Scale bars: A-D, 1

mm; E-G, 50 pm; H-J, 250 pm; K, 100 pm. Drawings by A. Pienaar.

HEPATOPHYTA: Aytoniaceae

59

purple-stained, tapering to narrow, connate tips.

Sporophyte with globose capsule, thin-walled

and lacking thickening bands. Figure 13. Spores

115.0- 152.5 pm diam., triangular-globular,

mostly yellow; wing thin, somewhat scalloped,

20.0- 22.5 pm wide, margin crenulate; distal

face convex, with network of 5-8, ± smooth,

angular, complete or incomplete alveoli across

and extending over wing to margin on both

sides, 25-30 x 20-25 pm, small subsidiary

alveoli sometimes present and extending over

crests of main ridges, 7.5-10.0 pm high; proxi-

mal face with prominent triradiate ridge, its

arms up to 25 pm high and continuous from the

pole across wing to margin, each of 3 facets

with rounded alveoli, up to 20 x 20 pm, some

with small, subsidiary alveoli, others appearing

smooth and hollowed out. Elaters 225-230 pm

long, 17.5 pm wide in centre, slightly tapering

to ends, 12.5 pm wide, sometimes branched,

bispiral, yellow. Chromosome number : unknown.

Plate 6A-C.

In the FSA area A. wilmsii is known from

Northern Province, Gauteng, Mpumalanga,

Swaziland and KwaZulu-Natal. Map 4. The

range of the species extends northward into

Zimbabwe and Angola (the type specimen of A.

angolensis ) as well as Malawi (Bizot et al.

1976). It may also grow in Zaire, a tentative con-

clusion based on the ovate scale appendages

illustrated by Vanden Berghen (1972: fig. 74H, I

and the distal spore face in fig. 74K), which sug-

gest this species, although the material was

merely designated as Asterella sp. by him.

Asterella wilmsii was also reported from

Mozambique by Arnell (1963a). The main dis-

tribution pattern along the mountains of the east-

ern part of the subcontinent suggests that it is an

Afromontane species with isolated western out-

liers. It grows on damp soil along streambanks

and waterfalls, sometimes in forested areas,

forming dense mats, occasionally in association

with A. bachmannii and Symphyogyna spp.

Asterella wilmsii is the largest of the southern

African species in this genus. It can be distin-

guished from the others by the single, ovate or

roughly triangular, large-celled appendage of the

ventral scales, by the distinctly lobed disc of the

carpocephalum, with purple paleae protruding

from the notches and by the slightly broader-

based paleae (up to 7 cells wide). The young,

almost sessile archegoniophore is surrounded by

purple paleae, which do not arch over it, as in A.

bachmannii. The disc is less papillose and the

spores are not as highly ornamented as those of

A. bachmannii, often lacking smaller subsidiary

alveoli in the large alveoli, which then appear to

be almost smooth and hollow and extend across

the wing. It is also not as widespread in southern

Africa as A. bachmannii and it is far less fre-

quently collected.

Vouchers: Edwards CH1270; Glen 1675;

Hardy 930; Kresfelder CH163; Mogg 37642;

Perold 2914.

CRYPTOMITRIUM

Cryptomitrium Austin ex Underw. in Bulletin Illinois State Laboratory of Natural History 2: 36

(1884); Schiffn.: 33 (1893); Steph.: 221 (1899); M.Howe: 43 (1899); A.Evans: 45 (1923); Hassel de

Menendez: 120 (1963); Perold: 149 (1994d). Type: C. tenerum (Hook.) Austin.

Platycoaspis Lindb. in Lindb. & Amell: 11 (1889).

Figure 13. — Asterella wilmsii. A, B, D, thallus: A, dorsal face with stalk and carpocephalum; B, ventral face; D, cross

section. C, carpocephalum from below; E, marginal cells. F, G, air pore; F, cells and oil cell from above; G, c/s with part of

air chamber. H, ventral scale; I, c/s of stalk; J, paleae from summit of stalk. A, I, J, S.M. Perold 2632 ; B, C, H. Anderson

I2l9a\ D, E, Perold & Koekemoer 2836\ F-H, Perold & Koekemoer 2830. Scale bars: A-D, 1 mm; E-G, 50 pm; H, I, 250

pm; J, 100 pm. Drawings by A. Pienaar.

60

HEPATOPHYTA: Aytoniaceae

Plate 6. — Spores and elaters. A-C, Asterella wilmsii: A, distal face; B, proximal face; C, elater. D-F,

Cryptomitrium oreades; D, elater; E, distal face; F, proximal face. A, Sim CH12679; B, Doidge 3187; C, Perold &

Koekemoer 2836; D, E, Van Rooy 3051; F, Perold & Duckett 3228. A, D, x 420; B, x 350; C, x 440; E, x 600; F, x 570.

HEPATOPHYTA: AYTONIACEAE

61

Thalli smallish to medium-sized, in loose patches; green, somewhat spongy and delicate.

Branches simple or rarely 1-3 times pseudodichotomously furcate, sometimes with apical or ven-

trolateral innovations, oblong to obovate, apex slightly notched, with scale appendages recurved

over edge; groove absent, thallus dorsally rather flat to slightly concave, margins thin, acute, scal-

loped or irregularly crenate, green or brownish purple; flanks sloping very obliquely, deep purple

and striate or green; ventral face medianly keeled. Scales ventral, small, in 2 rows, one on either

side of keel, roughly triangular or broadly ovate, dark red or reddish pink, with 1 or 2(3) filiform

appendages, margins occasionally with slime papillae, a few scattered oil cells present.

Dorsal epidermis hyaline, cell walls slightly thickened, with trigones prominent but not bulging,

or lacking trigones, oil cells occasional or absent; air pores small, simple, slightly raised, sur-

rounded by 3 or 4 concentric rings of 6-8 cells in each, radial walls not thickened. Assimilation tis-

sue medianly with 3 or 4 storeys of empty air chambers, reduced to single storey at margin, bound-

ing walls unistratose, chlorophyllose; storage tissue with closely packed, angular cells, not restrict-

ed to keel.

Autoicous, sometimes protandrous. Androecia in groups or rows, with sunken antheridia open-

ing into conical papillae above. Gynoecial receptacle raised on stalk arising ventrolaterally at

margin (in single southern African species) or dorsally at apical notch of thallus in extra southern

African species; carpocephalum disciform-round, flattish on top, margins crenate, with one layer

of air chambers opening above via compound air pores, below with (2)3-6 capsules. Stalk naked,

slender, yellowish, lacking air chambers, but with 1 rhizoid furrow. Involucre membranous, bil-

abiate, lips parted by elongated radial cleft, this eventually opening and gaping. Pseudoperianth

absent. Sporophyte with very short seta, foot bulbous, capsule nearly globose, wall thin, unis-

tratose, apically bistratose, inner cells with thickening bands, dehiscing by operculum shed at

annulus. Spores triangular-globular, winged; distal face with ± reticulate ornamentation, or with

thick sinuate ridges; proximal face with thin, tall, conspicuous triradiate mark, each facet with

incomplete alveoli. Elaters long, tapering, bispiral. Chromosome number: n = 9 [in C.

himalayense (Mehra (1948)].

Worldwide only three species have been described in this genus: C. tenerum from North

America (California and Washington State), as well as from Latin America (Mexico, Costa Rica,

Guatemala, Chile and Argentina); C. himalayense is from India; recently, the genus was reported

for the first time for the African continent, with the description of C. oreades from the Mountain

Kingdom of Lesotho (Perold 1994d).

Cryptomitrium species can be recognized, when fertile, by a flattish disciform-round car-

pocephalum, with 3-6 ventrally borne capsules, each protruding from a bilabiate, radially arranged

involucre; it is raised on a stalk with one rhizoid furrow but no air chambers.

Cryptomitrium oreades Perold in Botha-

lia 24: 149 (1994d). Type: Lesotho, 1 km from

New Oxbow Lodge on road to Mokhotlong, +

'/2 km from bridge, to the left, along Tiholohatsi

River, at interface between basalt rock slope

and grassy fringe, under large boulder in wet

seepage area, on soil, in alpine heath-grassland,

alt. ± 2 900 m, April 1994, Perold & Duckett

3228 (PRE, holo.).

Thalli medium-sized, in loose patches; green,

faintly areolate, air pores small, enlarging proxi-

mally, margins irregularly crenate to wavy, deep

purple underside visible through thin dorsal tis-

sue; when dry, thallus margins incurved or

clasped together. Branches simple or once pseu-

dodichotomously furcate, broadly linear to

oblong, up to 12 mm long, 3-5(-6) mm wide,

(450-)600-800 pm thick medianly, in section

HEPATOPHYTA: Aytoniaceae

HEPATOPHYTA: Aytoniaceae

63

6-8 times wider than thick, apex slightly notched,

with purple filiform tips of scale appendages

recurved over edge; groove absent, thallus dor-

sally flat to slightly concave, margins acute, thin;

flanks sloping very obliquely, purple; ventral

face medianly keeled. Scales in 2 ventral rows,

roughly triangular to transversely rectangular,

dark red or reddish pink, smallish, body 300-410

pm long, margins here and there with slime

papillae, base flat, 600-750 pm wide, narrowed

above, with 1 or 2(3) filiform appendages,

150-590 pm long, basal cells in 2 rows, soon

uniseriate, small oil cells scattered throughout

scale.

Dorsal epidermal cells unistratose, hyaline,

walls slightly thickened, trigones prominent,

irregularly shaped or oval, 25.0-42.5 x 20.0-

32.5 pm; air pores slightly raised, simple, 32.5 x

27.5 pm, surrounded by innermost ring of 6-8

small collapsed cells, then by 2 concentric rings

of 6-8 larger cells in each, radial walls not thick-

ened. Assimilation tissue 280-450 pm thick, air

chambers empty, in 3 storeys, bounding walls

chlorophyllose; storage tissue cells closely

packed; oil cells scattered throughout tissues.

Autoicous. Androecia in diffusely arranged

groups of antheridia sunken into dorsal tissue of

thallus, opening into conical papillae. Gyno-

ecial receptacles raised on stalk at maturity,

mostly single, rarely 2 adjacent; carpocephalum

disciform-round, not lobed, green, turning

brown with age, 2.5— 4.2 mm diam., rather flat-

tish on top, with one layer of elongated air

chambers, opening via compound air pores, 3-6

capsules borne below. Stalk erect, arising ven-

trally from below flank at side of keel, emerg-

ing laterally, close to dorsally borne antheridial

group, 3-5 mm long, up to 490 pm wide, with

single rhizoid furrow, base red, partly covered

with purple scales, otherwise yellowish, summit

surrounded by a few hyaline, filiform paleae.

Map 6.— A Cryptomitrium oreades

A Mannia capensis

□ Athalamia spathysii

Involucre membranous, formed by lips of elon-

gated radial clefts, which eventually widen,

exposing capsules. Sporophyte with short seta,

capsule globose, 1100 pm diam., wall unis-

tratose, apical cap bistratose, cells in inner layer

thicker-walled, smaller, with rod-like thicken-

ings, cap shed at annulus by dehiscence. Figure

14. Spores (77. 5-)85. 0-95.0 pm diam., light

brown, semitransparent, triangular-globular;

wing 7.5 pm wide, undulating and somewhat

plicate, margin irregular; distal face convex

with ornamentation hardly reticulate or with

thick, sinuate ridges up to 5 pm high, irregular-

ly branched and wavy, separated by deep fis-

sures; proximal face with conspicuous triradiate

mark, thin, tortuous, ± 7.5 pm high, extending

onto wing, each facet with irregular, branching

ridges, forming incomplete alveoli. Elaters

light brown, bispiral, 210-275 pm long and 10

pm wide at widest part, tapering to tips, 5 pm

wide. Chromosome number: unknown. Plate

6D-F.

Up to now C. oreades is known from only

two localities in Lesotho, growing at high alti-

Figure 14. — Cryptomitrium oreades. A, B, F, thallus: A, dorsal face with carpocephalum on stalk emerging at side;

B, ventral face; F, cross section. C, carpocephalum seen from below; D, ventral scale; E, c/s of stalk. G, H, air pore: G, from

above; H, c/s with part of air chamber. I-K, capsule wall: I, thin, unistratose portion; J, bistratose apical portion with thick-

enings, from above; K, c/s of bistratose portion. A-C, E, F, I-K, Van Rooy 3051 ; D, G, H, Perold & Duckett 3228. Scale

bars: A-C, F, 1 mm; D, 500 pm; E, 250 pm; G-K, 50 pm. Drawings by G. Condy.

64

HEPATOPHYTA: AYTONIACEAE

The species is characterized by a disciform-

round carpocephalum borne on an erect, single-

furrowed stalk which arises ventrally at the side

of the keel and emerges laterally at the thallus

margin in close proximity to the dorsally situat-

ed antheridial group.

tude in association with the moss Gymno-

stomum aeruginosum J.E.Sm. Map 6.

Cryptomitrium oreades differs from the

other two species in the genus mainly by the lat-

eral position of its stalk. In C. tenerum and C.

himalayense the stalk is dorsally situated near

the apex of the thallus; the thalli are also thinner

and more delicate than those of C. oreades.

Vouchers: Perold & Koekemoer 3749, 3750',

Van Rooy 3051 .

MANNIA

Mannia Opiz, Beitrage zur Naturgeschichte 12: 646 (1829); Frye & L.Clark: 60 (1937); R.M.Schust.:

601 (1953); Shimizu & S.Hatt.: 60 (1953); S.W.Arnell: 267 (1957); S.W.Arnell: 71 (1963a);

R.M.Schust.: 177 (1992c); Perold: 9 (1994a). Type: M. raddii Opiz = M. triandra (Scop.) Grolle.

Grimaldia Raddi: 356 (1818); Steph.: 792 (1898); M.Howe: 40 (1899); A.Evans: 43 (1923); Sim: 21 (1926). Type: G.

dichotoma Raddi, nom. illegit.

Synonymy partly after Grolle: 56 (1983a).

Thalli smallish to medium-sized, in crowded patches; bright green, sometimes laterally reddish

or bronzed, margins black, somewhat scalloped, firm, compact, rather leathery, lacunose proxi-

mally. Branches simple or once, rarely twice, pseudodichotomously furcate, or with apical or ven-

trolateral innovations, linear or strap-shaped, apex + entire, black tips of scale appendages recurved

over edge; groove absent, thallus dorsally flat to slightly concave, margins rather thin, acute; flanks

sloping obliquely, black and shiny; ventral face medianly broadly keeled. Scales ventral, in 2 rows,

obliquely triangular or semilunate, red-black, with 1 or 2 linear-lanceolate appendages, not con-

stricted at base, a few scattered oil cells present.

Dorsal epidermis hyaline, cell walls thin to thickened, with trigones; air pores simple, incon-

spicuous, slightly raised, surrounded by 2 or 3 concentric rings of 5-7 cells in each, radial walls

not thickened. Assimilation tissue with 2 or more storeys of repeatedly subdivided air chambers,

generally without chlorophyllose filaments, bounding walls complete or incomplete; storage tissue

well developed, with closely packed, angular cells; few cells with an oil body.

Dioicous, rarely autoicous, then androecia and gynoecia generally on different branches.

Androecia with antheridia sunken in 2 to several rows along centre of branches in the single south-

ern African species, otherwise in small, median, round or oval discs, opening above into conical

papillae. Gynoecial receptacle emerging from apical sinus formed by subsequent growth of thallus

lobes of main or ventrolateral branch; carpocephalum domed to low conical, centrally papillose

with compound air pores, not, or scarcely lobed beneath. Stalk length variable, with one rhizoid

furrow, at base and summit often with paleae. Involucre membranous, wide-mouthed and bell-

shaped, not bilabiate. Pseudoperianth absent. Sporopliyte with short seta, globose capsule protrud-

ing, wall lacking thickening bands, dehiscing by discrete apical lid. Spores roughly triangular-glob-

ular; distal face with conspicuous hemispherical bullae, sometimes collapsed; wing thick and undu-

lating; proximal face on raised platform, with low triradiate mark. Elaters tapering, bi- or trispiral.

Chromosome number, n = 9.

Mannia is said by Schuster (1992c) to be a relatively large genus with ± 18 species worldwide,

but Engel (1990) states that there are only six. All of them, except M. capensis, are from the north-

ern hemisphere.

HEPATOPHYTA: AYTONIACEAE

65

The genus was originally known as Grimaldia Raddi, but the specimen on which it was based,

contained two elements. Evans (Herzog 1938) showed that the name, Grimaldia , is illegitimate and

recently Grolle (1983b) submitted a proposal to conserve the name, Mannia Opiz (1829) against

Cyathophora Gray (1821). Grolle created two subgenera: Amelliella (Mass.) Grolle, with section

Neesiella (Schiffn.) Shimizu & S.Hatt. and Xeromannia Grolle with sections Xeromannia and

Sindonisce.

Schuster (1953, 1992c) is, however, convinced that the division of Mannia into subgenera, based

largely on the form of the aerenchyma tissue ‘compact’ versus ‘loose’, is artificial. He concluded

that it ‘is perhaps an artifact based on environmentally induced distinctions’ (Schuster 1956).

Mannia capensis (Steph.) S.W.Arnell in

Mitteilungen der Botanischen Staatssammlung,

Munchen 16: 263 (1957); S.W.Arnell: 72 (1963a);

O.H.Volk: 233 (1979); Perold: 9 (1994a). Type:

Bloemfontein, leg. Rehmann (G, holo.!).

Thalli smallish to medium-sized, in crowded

patches; bright green, sometimes laterally red-

dish or bronzed, firm, compact, faintly areolate,

air pores numerous, small, margins with narrow

black borders distally, gradually widening prox-

imally, somewhat scalloped; when dry, thallus

margins tightly incurved and branches almost

tubular. Branches simple or once, rarely twice,

pseudodichotomously furcate, sometimes with

apical or ventrolateral innovations, linear or

strap-shaped, up to 12 mm long, 2-4 mm wide,

525-775 pm thick medianly, in section 4 or 5

times wider than thick, apex entire, tips of ven-

tral scales reflexed over edge; groove absent,

thallus flat to slightly concave dorsally, margins

acute, quite thin; flanks sloping obliquely; ven-

tral face medianly broadly keeled, black. Scales

in 2 ventral rows, obliquely triangular or semi-

lunate, black to reddish black, body ± 600 pm

long, margins sometimes with few mucilage

papillae, base concave, ± 600 pm wide, nar-

rowed above without constriction to 1 or 2(3)

linear-lanceolate appendages, up to 110 pm

long, ± 17 pm wide at base, tapering to acute

apex, oil cells scattered throughout.

Dorsal epidermal cells unistratose, hyaline,

trigones conspicuous but not bulging, external-

ly covered with minute spicules, polygonal,

27-30 x 15-25 pm; air pores slightly raised,

simple, ± 25 x 15 pm, surrounded by innermost

ring of 7 small, collapsed cells, then by 2 con-

centric rings of 7(8) larger cells in each, radial

walls not thickened. Assimilation tissue

200-250 pm thick, air chambers in several

storeys, densely crowded and incompletely

bounded by unistratose walls, difficult to distin-

guish between bounding cells and those form-

ing chlorophyllose filaments; storage tissue

well developed, cells angular; oil cells scattered

throughout tissues.

Dioicous, rarely monoicous, but gametangia

generally on different branches. Androecia with

2 to 4 rows of sunken antheridia along centre of

branches, opening into conical papillae.

Gynoecial receptacles terminal when young,

sessile, knob-like, in V-shaped, apical sinus,

surrounded by numerous, arched, dark purple

lanceolate paleae, up to 1150 pm long, 4-6 cells

wide at base, narrowing to one cell wide at

apex, at maturity raised on stalk; carpoce-

phalum ± 2 mm across, straw-coloured, domed

to low conical, papillose centrally with com-

pound pores, not or scarcely lobed below, bear-

ing (1)2-4 capsules. Stalk 5-25 mm long, cylin-

drical, 400 pm wide, with single rhizoid furrow,

only a few paleae carried along and also present

at summit, but obscured. Involucres membra-

nous, wide-mouthed and bell-shaped, each with

single capsule. Sporophyte with short seta, cap-

sules protruding, globose, dark brown, wall

lacking annular thickenings, dehiscing by well-

formed lid along row of smaller cells. Figure

15. Spores 75-80 pm diam., polar, roughly tri-

angular-globular, light brown, semitransparent;

wing lighter, straw-coloured, 7.5 pm wide,

porate at each of 3 angles (or in between as

well), wavy and undulating, inflated and twist-

ed in side view; distal face convex, bearing

K

HEPATOPHYTA: Aytoniaceae/Cleveaceae

67

10-13 crowded and very conspicuous, hemi-

spherical bullae, ± 22 pm wide, mostly well

separated from each other, occasionally 1 or 2

collapsed, proximal face with raised base, trira-

diate mark present but weak, slightly raised or

not, arms not extending to edge, with shallow,

crowded and overlying alveoli in centre, both

faces generally covered with granules. Elaters

reddish brown, tapering toward ends, 212-275

pm long, 12.5 pm wide in centre, 7.5 pm wide

at tips, bi- or trispiral. Chromosome number :

n = 9. Plate 7A-C.

The species has been reported from Zim-

babwe (Best 1990) and Bizot & Poes (1982)

reported its occurrence as disjunct in East

Africa on the Uluguru Mountains, where it

grows in open, exposed sites. Although not

common, Mannia capensis has been collected

over a wide area in southern Africa. It is known

from Namibia, Northern Province, North-West,

Gauteng, Mpumalanga, Free State, Northern,

Western and Eastern Cape. Map 6. It is found in

rocky clefts or on shallow soil covering granite,

quartzite, sandstone or sometimes dolomite,

occasionally in association with other liver-

worts such as Riccia spp., Plagiochasma spp. or

with Exormotheca pustulosa. It is a pronounced

xerophyte, with the storage tissue markedly

thicker than the assimilation tissue.

Fertile plants of M. capensis can be distin-

guished quite readily from other members of

the Marchantiales by the stalked, domed and

unlobed carpocephala, lacking a pseudoperi-

anth. Sterile specimens are more difficult to

distinguish, particularly from Targionia hypo-

phylla and small Asterella plants. In T. hypo-

phylla, however, the dorsal air pores are larger,

and, when dry, white-encircled; in Asterella

species, with the exception of A. muscicola, the

air pores and air chambers are generally diffi-

cult to detect from above, fresh or dry.

Vouchers: Brusse 4206; Burrows 2521 ; Glen

2461; Koekemoer 637a; Mogg 37590; Perold

947.

CLEVEACEAE

Cleveaceae Cavers in New Phytology 10: 42 (1911); Mull.Frib.: 368 (1951-1958); Hiissel de

Menendez: 133 (1963); R.M.Schust.: 103 (1992c). Type: Clevea Lindb.

Astroporae Leitg. (1881).

Cleveideae Solms: 15 (1899).

Cleveoideae Lotsy: 103, 114(1909).

Suuteriaceae A. Evans: 35 (1923).

Thalli medium-sized, in crowded patches; bright green or glaucous green, sometimes purple

along margins. Branches simple or once pseudodichotomously furcate, occasionally with ventro-

lateral or apical innovations, ligulate or oblong to broadly ovate to obovate, apex hardly notched,

tips of some apical scales projecting beyond or recurved over edge; groove absent, thallus medi-

anly concave dorsally, margins acute, thin, attenuate, scalloped and undulate, occasionally some-

what erect; flanks sloping obliquely or steep, sometimes deep purple; ventral face medianly keeled

Figure 15. — Mannia capensis. A-E, thallus: A, dorsal face of male with rows of antheridia; B, apical portion of female

with stalk arising from apical sinus and at its tip bearing unlobed archegoniophore, involucres partly covering 2 capsules;

C, ventral face showing scales; D, cross section; E, c/s of male through antheridia. F, G, air pore: F, c/s dorsal cells and

assimilation tissue; G, from above. H, paleae from foot of stalk; I, c/s of stalk. J, K, scales: J, with 1 appendage; K, with 2

appendages. A-D, G-I, K, Glen 2 117\ E, F, J, Koekemoer 637. Scale bars: A-C, 1 mm; D, E, 500 pm; F, G, 50 pm; H, I,

250 pm; J, K, 500 pm. Drawings by A. Pienaar.

68

HEPATOPHYTA: Aytoniaceae/Cleveaceae

Plate 7. — Spores and elaters. A-C, Mannia capensis: A, distal face; B, proximal face; C, elater. D-F,

Athalamia spathysii: D, elater; E, distal face; F, proximal face. A, B, Eyles CH1179\ C, Volk 00828 ; D-F, Volk

00589. A, B, x 700; C, x 410; D, x 1290; E, x 740; F, x 620.

HEPATOPHYTA: CLEVEACEAE

69

or flattish. Scales ventral, in 2 or more, regular or irregular rows, obtusely triangular, hyaline or

purple-red, with long-acuminate appendage, not constricted at base, margins sometimes with slime

papillae, tips extending beyond thallus margins or not, oil cells absent.

Dorsal epidermis hyaline or with chloroplasts, cell walls thin, with or without minute trigones;

air pores simple, small, slightly raised, encircling wall ± thickened, often stellate, surrounded by

one ring of cells, radial walls generally thickened. Assimilation tissue with one or several storeys

of empty air chambers, cells in bounding walls chlorophyllose; storage tissue poorly or well devel-

oped; with occasional oil cell, but mostly without; with or without mycorrhiza.

Asexual reproduction absent.

Monoicous or dioicous. Androecia with antheridia hardly aggregated, in loose, sessile, ill-

defined groups or in median rows along length of thallus, opening into projecting papillae.

Gynoecial receptacle single or several along midline, arising from dorsal depression, proximal to

apex of branch; carpocephalum sessile when young, surrounded by tuft of hyaline or reddish

paleae, at maturity raised on stalk, developing (l-)2 or 3 arms, air chambers and pores vestigial or

absent. Stalk ± colourless, lacking rhizoid furrow, at summit with few paleae. Involucres directed

obliquely upwards, often somewhat beaked or pointed at upper ends, basally connate. Sporophyte

with globose capsule on short seta, obliquely erect, wall with thickening bands, dehiscing by irreg-

ular valves. Spores rounded distally, somewhat flattened proximally, lacking triradiate mark, dense-

ly covered with conical spines. Elaters long, tapering, bispiral. Chromosome number, n = 9, 18.

Three genera, Athalamia Falc., Peltolepis Lindb. and Sauteria Nees are classified in the family

Cleveaceae, but neither of the latter two occur in southern Africa. The above family description

excludes them.

The family is known from alpine and arctic or sometimes from warm, low-lying areas.

ATHALAMIA

Athalamia Falc. in Annals and Magazine of Natural History, Ser. 2,1: 375 (1848); Falc.: 397

(1851); Shimizu & S.Hatt.: 52 (1954); S.W.Arnell: 57 (1963a); Perold: 207 (1993b). Type:

Athalamia pinguis Falc.

Clevea Lindb. 9: 289 (1868); Steph.: 769 (1898); Schiffn.: 29 (1893); M.Howe: 36 (1899); Mull.Frib.: 368 (1951-1958);

Hassel de Menendez: 133 (1963). Type: Clevea hyalina (Sommerf.) Lindb.

Spathysia Nees ex Trevis.: 439 (1877). Type: Spathysia lindenbergii Trevis. nom. illegit.

Gollaniella Steph.: 74 (1905). Type: Gollaniella pusilla Steph.

Characters the same as those of the family as represented in southern Africa.

There are at least 10 or even 15 species world-wide in the genus Athalamia, with A. spathysii

the only representative in southern Africa; A. pulcherrima (Steph.) S.Hatt. from Ethiopia is distin-

guished by larger, hyaline, ventral scales and cells with much thickened radial walls surrounding

the dorsal air pores. Another species recorded from Africa in Algeria, is Clevea ( Athalamia ) tra-

butiana Steph., but it is regarded by Grolle (1976) as conspecific with A. hyalina (Sommerf.)

S.Hatt.; Clevea ( Athalamia ) crassa Trabut from the Atlas Mountains (Magreb) is also very similar

to A. hyalina (Mull.Frib. 1951-1958), but Grolle (1976) considers it to be a 'nom. inval .’

70

HEPATOPHYTA: Cleveaceae

J

K

HEPATOPHYTA: Cleveaceae

71

According to Muller (1939), Arnell (1963a), Vanden Berghen (1965) and Volk (1979) oil bod-

ies are absent in the genus Athalamia (= Clevea). Perold (1993b) also found them to be absent in

A. spathysii, but fresh material was not available for study. Shimizu & Hattori (1954), however,

reported oil cells in Athalamia glauco-virens as well as in A. nana (Shimizu & Hattori 1955).

Schuster (1992c) states that sparse, scattered oil cells may be present or absent.

Shimizu & Hattori (1954) also stated that ‘whether the pores of the thallus are stellate or not,

should not be considered a characteristic of generic value’. Sometimes they had observed pores

with both thickened radial walls (stellate) or with thin walls (not stellate) on the same plant.

Asexual reproduction is said to be absent. Stephani (1895) suspected that adventitious growth

in the form of ventral shoots from the costa was partly the reason for the ‘dichten verfilzten niedri-

gen Rasen’ in Clevea pulcherrima Steph. As in Plagiochasma spp., the apical part of the thallus

continues to grow and increase in length, beyond the archegoniophore, after the latter has differ-

entiated.

Athalamia spathysii (Lindenb.) S.Hatt.

in Shimizu & S.Hatt. in Journal of the Hattori

Botanical Laboratory 12: 54 (1954); S.W.Ar-

nell: 57 (1963a); Vanden Berghen: 168 (1965);

O.H.Volk: 230 (1979); Perold: 207 (1993b).

Type: Greece, Corfu, leg. Spathys (W, holo.!;

STR, iso.).

Marchantia spathysii Lindenb.: 104 (1829); Bisch.: 1018

(1835). Dumortiera spathysii (Lindenb.) Nees: 171 (1838);

Gottsche et al. : 546 (1844-1847). Clevea spathysii

(Lindenb.) Mull.Frib.: 75 (1940a); Mull.Frib.: 374 (1951-

1958).

Plagiochasma rousselianum Mont.: 334 (1838b). Clevea

rousseliana (Mont.) Leitg. in Steph.: 771 (1898). Type:

Algeria, ‘Boudjareah’, Roussel.

Thalli medium-sized, in crowded patches;

bright green, areolate, air pores tiny, slightly

raised, margins wine-red, scalloped, undulate,

often somewhat erect, older parts dead; when

dry, thallus margins incurved and tightly

clasped together above. Branches simple or

once pseudodichotomously furcate, oblong to

broadly ovate or obovate, (3.5-)5.0-12.0 mm

long, 2.5-7. 5 mm wide, 825-1075 pm thick

medianly, in section 3-7 times wider than thick,

apex slightly notched, with tips of 2 or 3 purple-

red scales recurved over edge; groove absent,

thallus dorsally slightly concave medianly, mar-

gins acute, thin; flanks sloping obliquely, pur-

ple; ventral face medianly keeled, green. Scales

in 2 ventral rows, obtusely triangular, purple-

red, body 550-600 pm long, margins entire or

sometimes bluntly toothed on oblique side, base

± straight to slightly concave, 850-1000 pm

wide, narrowed above without constriction to

acuminate, apically tapering and pointed ap-

pendage, 575-750 pm long, 150-200 pm wide

at base, oil cells absent.

Dorsal epidermal cells unistratose, hyaline,

± polygonal, (32.5-)57.5-62.5 ± 30.0-42.5 pm,

thin-walled, but frequently thickened at corners;

air pores very slightly raised, simple, 7.5-12.5

pm wide, surrounded by one ring of 4— 6(— 7)

bluntly triangular cells, partly overlying adja-

cent dorsal cells, encircling and radial walls

mostly thickened, pores thus stellate. Assimila-

tion tissue 350-500 pm thick, air chambers

empty, in one storey, sometimes in several, walls

unistratose, chlorophyllose; storage tissue with

cells fairly densely packed together, rounded.

Figure 16. — Athalamia spathysii. A-D, thallus: A, dorsal face with stalked archegoniophore and several young ses-

sile ones; inset with archegoniophore and 2 dehiscing capsules; B, dorsal face with rows of antheridia; C, ventral face; D,

cross section. E-G, air pore: E, F, with thickened radial walls; G, c/s with dorsal epidermis and air chambers. H, ventral

scale; I, c/s of stalk; J, palea from top of stalk; K, L, capsule wall: K, cells with annular thickenings; L, cross section. A,

I-L, Volk 005R9-, B, Volk 6124\ C-H, Volk 00904. Scale bars: A-C, 2 mm; D, 1 mm; E-G, K, L, 50 pm; H, J, 200 pm; I,

100 pm. Drawings by A. Pienaar.

72

HEPATOPHYTA: Cleveaceae/Exormothecaceae

Monoicous, but occasionally only antheridia

or archegonia found. Androecia, with antheridia

in rows along entire middle of thallus, sunken,

opening into raised, conical papillae. Gynoecial

receptacle single or several, ± linearly and

acropetally arranged on dorsal face, sessile

when young, rounded and basally surrounded

by inconspicuous, filiform paleae, at maturity

raised on stalk; carpocephalum white to green-

ish white, central disc absent. Stalk cylindrical,

pellucid, 1 .6-7.0 mm long, 250 pm diam., with-

out rhizoid furrow; paleae eventually carried

upwards and only present at its summit, hyaline

or pink, basally 750 x 500 pm, apically with 4

or 5 filiform strands, up to 750 pm long. In-

volucres 1-3(4), connate at their bases, attached

to top of stalk, bilabiate by vertical cleft, each

one with single capsule. Sporophyte with cap-

sule globose, 1250 pm diam., borne obliquely

erect on seta with bulbous foot, dehiscing by

several irregular valves, wall unistratose, cells

with annular thickening bands. Figure 16.

Spores (60 — )65 — 75( — 78) pm diam., globular,

golden brown, semitransparent, both faces

thickly covered with dense conical spines, 5 pm

high and 15 pm wide at base, sprinkled with

fine granules; distal face convex; proximal face

without triradiate mark, somewhat flatter.

Elaters yellow-brown, slightly tapering toward

ends, 275-350 pm long, 7.5-10.5 pm wide in

middle, bispiral, very occasionally branched,

sometimes bent. Chromosome number: n = 9

(Bornefeld 1987); as Clevea rousseliana: n = 9

(Heitz 1927). Plate 7D-F.

Athalamia spathysii is known from Israel,

North Africa, the Canary Islands and the Medi-

terranean countries (Mull.Frib. 1951-1958); the

type specimen was collected at Corfu. Frey &

Kiirschner (1988) report it from Yemen and

Oman in the Arabian Peninsula, and state that

its distribution includes Turkey and Jordan. It

has also been reported from eastern Africa,

i.e. from Tanzania (= Tanganyika) by Vanden

Berghen (1965).

Athalamia spathysii has rarely been collect-

ed in southern Africa; the gatherings by Volk

(1979) are restricted to Namibia. It was recent-

ly also collected in the Eastern Cape. Map 6. It

grows in periodically dry areas, on soil overly-

ing slate, granite or sandstone, in rocky crevices

or under overhangs, where runoff may be con-

centrated and some protection against radiation

is afforded; sometimes it occurs together with

Plagiochasma spp. and Targionia liypophylla.

The species is distinguished by the areolate

dorsal surface of the thallus, small and slightly

raised, mostly stellate air pores, empty air

chambers, scales with acuminate appendages,

lack of oil cells, cell walls of capsule with spi-

ral thickenings and by bluntly spinous spores.

Sterile specimens of A. spathysii have been

confused with Asterella muscicola (Arnell 1957),

because of the stellate dorsal pores, but the lat-

ter does not grow in Namibia (Volk 1979), its

ventral scales have scattered oil cells, the stalk

has a rhizoid furrow and the capsule wall lacks

thickenings.

Vouchers: Perold 945; Schelpe 4763; Volk

00952, 6124.

EXORMOTHECACEAE

Exormothecaceae Mull.Frib. in Grolle, Journal of Bryology 7: 208 (1972); Mull.Frib. : 275

(1940b); Mull.Frib.: 397 (1951-1958); Hassel de Menendez: 192 (1963); S.W.Arnell: 74 (1963a).

Type: Exormotheca (Godm.) Mitt.

I hall i small to medium-sized to quite large, in crowded patches; silvery glaucous-green, mar-

gins not differentiated, dorsally completely covered with numerous conical evaginations of epi-

dermis, ventrally fleshy. Branches simple or once, sometimes twice (-3 times) pseudodichoto-

HEPATOPHYTA: Exormothecaceae

73

mously furcate, ligulate or narrowly to broadly linear or ovate, apex entire to shallowly notched,

apical (and other) scales mostly erect, only when dry recurved over edge; groove absent, thallus

dorsally slightly concave medianly, otherwise flat, margins somewhat obtuse, becoming more

acute proximally; flanks sloping obliquely to rather steeply; ventral face medianly rounded. Scales

ventrolateral, oblong to rounded or obliquely triangular, purple or hyaline with purple base, occa-

sionally with 1 or 2 appendages, or with long, filiform appendages at acute apex, margins often

toothed, extending to or above thallus margins, oil cells absent.

Dorsal epidermis unistratose, hyaline, thin-walled, without trigones, raised as pustular or coni-

cal evaginations over low or tall air chambers; air pores simple, at or near apices of evaginations,

surrounded by thin-walled cells. Assimilation tissue with air chambers elevated, low or tall, basal-

ly occupied by densely crowded, chlorophyllose filaments in one storey; storage tissue occupying

ventral part of thallus, in somewhat loose mesh of open, round spaces, surrounded by smaller,

angular cells; with scattered oil cells.

Asexual reproduction rare.

Monoicous or ?dioicous. Androecia with antheridia sunken in rows in shallow groove, along

middle of thallus, sometimes interrupted, necks protruding conspicuously, development of air

chambers here temporarily suppressed. Gynoecial receptacle raised on stalk or sessile; car-

pocephalum with central core of parenchymatous tissue, supporting filament-containing air cham-

bers that open above via simple air pores, capsules usually borne laterally. Stalk, when present, with

single rhizoid furrow, lacking paleae. Involucre tubular or not, bilabiate, lateral extensions of cen-

tral area or dome. Sporophyte 1 or 2 per involucre, sometimes none, capsules globose, exserted on

seta or not, wall with semi-annular thickenings, dehiscing by 4 or 5 irregular valves. Spores smallish

to large, triangular-globular; distal face with large, hollow, conical papillae covered with granules;

proximal face without distinct triradiate mark, heavily encrusted with granules. Elaters long or

short, tapering or blunt, tri- or unispiral. Chromosome number, n = 16, 18, 32.

Three genera, Exormotheca (Godm.) Mitt., Aitchisoniella Kashyap and Stephensoniella

Kashyap are classified in the family Exormothecaceae, but the last two are restricted to India. The

family description above excludes them. The genus Exormotheca is widespread and is known from

several Mediterranean countries, Atlantic and Indian Ocean islands, north, tropical and southern

Africa, the Middle East, India, and Sri Lanka (Ceylon), as well as from South America (Brazil and

Argentina) and possibly Mexico.

EXORMOTHECA

Exormotheca (Godm.) Mitt, in Natural history of the Azores or Western Islands: 325 (1870);

Schiffn.: 29 (1893); Solms: 2 (1897); Steph.: 218 (1899); Mull.Frib.: 292 (1905-1916); Schiffn.:

40 (1942); Mull.Frib. : 398 (1951-1958); Hassel de Menendez: 193 (1963); Perold: 15 (1994b).

Type: E. pustulosa Mitt.

Myriorrhynchus Lindb. & Amell: 8 (1884). Type: M. fimbriatus Nees.

Corbierella Douin & Trab.: 321 (1916). Type: C. algeriensis Douin & Trab.

Characters the same as those of the family as represented in southern Africa.

74

HEPATOPHYTA: Exormothecaceae

Plate 8. Spores and elaters. A-C, Exormotheca pustulosa: A, distal face; B, proximal face; C, elater.

D-F, E. holstii: D, elater; E, distal face; F, proximal face. A, B, Arnell 791 \ C, Perold & Koekemoer 3133\ D-F

Holst 3107. A, x 690; B, x 660; C, x 930; D, x 860; E, x 380; F, x 390.

HEPATOPHYTA: EXORMOTHECACEAE

75

Three sections are recognized in the genus Exormotheca: Exormotheca, for E. pustulosa, E.

tuberifera and E. ceylonensis\ Corbierella (Douin & Trab.) Schiffn., for E. welwitschii, E. alge-

riensis and E. holstiv, and Myrriorhynchus Lindb. & Arnell, for E. fimbriata (Schiffner 1942). The

last section does not occur in southern Africa, only in Brazil and Argentina, and is distinguished by

scales with fan-shaped, multibranched, filamentous appendages.

Key to sections and species of Exormotheca in southern Africa

Thalli smallish; assimilation tissue with air chambers inflated into low, conical protuber-

ances, basal 2/3 occupied by chlorophyllose filaments; ventral scales small, oblong to

rounded, often purple, with 1 or 2 filiform appendages; gynoecial receptacle mostly on

longish stalk; elaters long, trispiral section Exormotheca: 1. E. pustulosa

Thalli medium-sized to quite large; assimilation tissue with air chambers inflated into tall

conical protuberances, basal V5-V3 occupied by chlorophyllose filaments; ventral

scales large, ± obliquely triangular, hyaline, apex with up to 5 filiform appendages;

gynoecial receptacle sessile; elaters short, unispiral or ringed

section Corbierella: 2. E. holstii

Exormotheca section Exormotheca

Thalli smallish with low, conical air chambers, lower ± 2/3 filled with chlorophyllose cell fila-

ments. Scales oblong or rounded, purple or partly hyaline. Gynoecial receptacles stalked. Elaters

rather long, trispiral. Exormotheca pustulosa belongs here.

1. Exormotheca pustulosa Mitt, in

Natural history of the Azores or Western Islands:

326 (1870); Solms: 2 (1897); Steph.: 218

(1899); K.I.Goebel: 244 (1905); Miill.Frib.: 292

(1905-1916); Schiffn.: 46 (1942); Miill.Frib.:

399 (1951-1958); S.W.Arnell: 74 (1963a);

O.H.Volk: 232 (1979); Perold: 15 (1994b).

Type: Madeira, Pico de Barcellos, leg. Johnson

(NY, holo.!).

E. africana Steph.: 18 (1917). Type: Transvaal, in water-

fall gorge near Belfast, leg. Pole Evans (G).

Thalli rather small, in crowded patches;

glaucous-green, with numerous conspicuous,

partly adjoined conical or pustular evaginations

of dorsal epidermis into air chambers, pores

raised, at or near their apices; when dry, flanks

covered by imbricate, purple or partly hyaline

scales, generally tightly incurved over whitish,

dorsal face. Branches simple, or once, occa-

sionally twice (-3 times) pseudodichotomously

furcate, linear to ligulate, up to 8 or 9 mm long,

2(-3) mm wide, ± 1000 pm thick medianly, in

section 2 or 3 times wider than thick, apex

slightly concave medianly, scales not reflexed

over edge; groove absent, thallus dorsally ± flat,

margins rather obtuse, covered by air chambers,

scales extending above or hardly so; flanks

sloping obliquely; ventral face quite strongly

keeled medianly, green. Scales covering flanks,

imbricate, oblong or rounded, purple or partly

hyaline, 500-1000 x 540-850 pm, occasionally

with 1 or 2 appendages at margin, oil cells

absent.

Dorsal epidennal cells unistratose, hyaline,

polygonal, 30-75 x 22-25 pm, fairly thin-

walled, without trigones, elevated into conical

protuberances ± 300 pm high, 150-180 pm

wide, in (8)9-11 irregular rows across width of

thallus; air pores raised to or near top of cone,

simple, round or oval, up to 62 pm wide, sur-

rounded by innermost ring of ± 8 slightly bent, ±

rectangular, thin-walled cells, then by an irregu-

lar ring of smaller, polygonal, thicker-walled

cells. Assimilation tissue ± 200 pm thick, occu-

pying lower ± 2/3 of air chambers, consisting of

densely crowded filaments, sometimes branch-

ing, containing numerous chloroplasts; storage

tissue loosely composed, with larger empty

76

HEPATOPHYTA: Exormothecaceae

HEPATOPHYTA: Exormothecaceae

77

spaces (so-called ‘slime’ cells), encircled by

smaller cells; a few oil cells in between.

Asexual reproduction by ventral, scale-clad,

spherical tubers (Knollchen).

Monoicous (or rarely ?dioicous). Androecia

in 1-3 rows along middle of thallus, close to

female receptacle (distal or proximal to it),

antheridia sunken, in shallow groove, necks pro-

truding, air chambers here suppressed. Gynoe-

cial receptacles apical or just proximal to bifur-

cation of 2 terminal branches, when young ses-

sile, at maturity raised on stalk; carpocephalum

above with filament-containing air chambers

opening via hardly raised, simple air pores, fre-

quently hammer-like in shape, up to 3 mm

across, capsules exserted laterally, one on either

side, sometimes bearing only 1 capsule, and then

erect and oblong. Stalk basally purple-streaked,

remainder yellowish, length variable, up to 10

mm, 350 pm diam., with single rhizoid furrow,

top of stalk loosely sheathed in short, collar-like

outgrowth at base of head. Involucres bilabiate.

Sporophyte with long seta, capsule ± globose,

wall unistratose, upper part forming an opercu-

lum, its cells somewhat smaller, otherwise simi-

lar to the rest, with semi-annular thickenings,

dehiscing by shedding lid and by 4 or 5 irregu-

larly shaped valves folding back, petal-like.

Figure 17. Spores 70-75 pm diam., polar, trian-

gular-globular, honey-brown; distal face round-

ed, with up to ± 50 crowded, hollow, conical

papillae, 10 pm high, 10 pm wide, walls of

papillae composed of numerous adjoining gran-

ules, stacked into tiny pillars in some areas and

only exposed where wall breaks down; proximal

face with vestigial triradiate mark or only part of

it occasionally present, entirely encrusted with

fine granules, wing absent, margin scalloped by

Map 7. — Q Exormotheca pustulosa

• E. holstii

protruding papillae on distal face. Elaters

honey-brown, not tapering toward ends, some-

times coiled, up to 150 x 10 pm, trispiral. Chro-

mosome number n = 16 (Bischler 1976). Plate

8A-C.

Exormotheca pustulosa is quite widespread

and is known from the following Mediterranean

countries: Portugal, Spain, France and Italy, as

well as from the Atlantic islands of Azores,

Madeira, the Canaries, Cape Verde and St

Helena, also from two island groups (or islands)

in the Indian Ocean: the Comores and Reunion

(Bischler 1976). It is further known from Saudi

Arabia, United Arab Emirates and Oman (Frey

& Kiirschner 1988) as well as from the follow-

ing African countries: Morocco, Chad, Ethi-

opia, and also from Kenya, Tanzania (Bizot &

Poes 1979), Angola, Zimbabwe and southern

Africa. In southern Africa E. pustulosa has been

quite rarely collected in the North-West and

Northern Province, Gauteng, Mpumalanga, as

well as in Free State, Lesotho and Western

Cape. Map 7.

Figure 17. — Exormotheca pustulosa. A, B, F, thallus: A, dorsal face from above, toward apices with rows of antheridia

in grooves and with young gynoecium at furcation; B, ventral face, showing scales; F, c/s, showing 2 antheridia. C, stalk

(cut off) emerging just proximal to furcation of thallus; D, ‘hammer-like’ head of carpocephalum with 2 dehisced capsules;

E, G, air pore: E, with air chamber, assimilation tissue filaments and some storage tissue cells; G, from above. H, scale. I,

J, capsule wall: I, cross section; J, from above. K, c/s of stalk with one rhizoid furrow. A, B, F, H, Perold 2604\ C, D, 1-K,

S.W Amell 791\ G, Reid 1107a. Scale bars: A-D, 1 mm; E, G, I, J, 50 pm; F, H, 500 pm; K, 100 pm. Drawings by A.

Pienaar.

78

HEPATOPHYTA: Exormothecaceae

Exormotheca pustulosa grows in association

with other liverworts, such as Riccia species

and Mannia capensis, on soil around granite or

sandstone outcrops, which are generally only

temporarily wet.

The species can be distinguished by its low

conical air chambers ± 2/3 filled with chloro-

phyllose cell filaments, by its small size, oblong

or rounded, mostly purple scales, its stalked car-

pocephala, its spore ornamentation and its sphe-

rical tubers.

Vouchers: Arnell 7913; Bosman CH1533;

Glen 2140; Perold 1207; Schelpe 5284.

Exormotheca section Corbierella (Douin & Trab.) Schiffn.

Thalli medium-sized to quite large; with tall conical air chambers, basal V5— V3 filled with

chlorophyllose cell filaments. Scales ventral, large, ± obliquely triangular. Gynoecial receptacles

sessile. Elaters short, unispiral or ringed. Exormotheca holstii is placed here.

2. Exormotheca holstii Steph. in Bulletin

de l’Herbier Boissier 7: 145 (1899); Schiffn.: 66

(1942); S.W. Arnell: 76 (1963a); O.H.Volk: 231

(1979); Perold: 18 (1994b). Type: Deutsch-Ost-

Afrika (= Tanzania), Muse, plains, in moist

sandy spots [regio campestris, in locis arenosis

humidis], leg. Holst 3107 ( G024591 , holo.!).

E. megastomata C.Marquand: 237 (1930). Type:

Transvaal, Krantz, 3 miles N of Middelburg, leg. F. van der

Merwe CH214 (BM, holo.), CH214 (PRE, iso.!);

BOL54643 (Duthie 5042) (iso.!).

E. youngii S.W.Ameli: 283 (1953b). Type: Transvaal,

Pilgrim’s Rest, Hendriksdal, on dry rocky veld, leg. E.M.

Young ( Duthie 5211) (BOL54651 , holo.!).

Thalli medium-sized to quite large, in

crowded patches; silvery green, dorsal epider-

mis evaginated into numerous conspicuous, tall,

conical air chambers, medianly narrow, some-

what lower, laterally mostly wider and taller, air

pores raised to near or at apices; when dry, dor-

sally concave to grooved along midline, scales

incurved over margins or erect. Branches sim-

ple or once, rarely twice or 3 times pseudodi-

chotomously furcate, broadly linear to ± ovate,

8— 1 5(— 22) mm long, (2.5-) 3.0-5.0(-7.0) mm

wide, 2125-2900 pm thick over midrib, in sec-

tion ± 1 '/2 times wider than thick, apex with

shallow notch; groove shallow toward apex,

thallus otherwise dorsally flat to medianly

slightly concave, margins obscured by air

chambers, scales mostly hidden; flanks sloping

steeply; ventral face rounded to flattish, green

or sometimes purple. Scales covering flanks,

hyaline with purple base, imbricate, obliquely

triangular, 1250-1625 pm long, vertical mar-

gins facing distally, ± entire, sloping margins

often toothed, apex with several branched or

unbranched, filiform appendages, base

900-1500 pm wide, oil cells absent.

Dorsal epidermal cells unistratose, hyaline,

variable in shape and size, ± thin-walled, raised

into tall 4—6-sided air chambers, in 8-12 irregu-

lar rows across thallus width, attached to each

other except for free, conical, apical part; air

pores located at or away from tip of cones, simple,

rounded or elongated, surrounded by one ring

of smaller cells. Assimilation tissue 350-400

pm thick, occupying basal V5-V3 of air cham-

bers, composed of densely crowded, sometimes

branched filaments, 7 or 8 cells long, filled with

chloroplasts; storage tissue an open mesh with

‘rounded spaces’, surrounded by smaller, most-

ly angular cells; oil cells toward top and base of

storage tissue.

Monoicous or dioicous or ?protandrous, very

rarely producing gametangia of both sexes

simultaneously. Androecia in 2-4 irregular rows

along midline of thallus, in 1 or 2 successive lin-

ear groups, antheridia sunken, necks protruding

conspicuously, development of central air cham-

bers temporarily suppressed. Gynoecial recepta-

cles developing near apex of thallus (which con-

HEPATOPHYTA: Exormothecaceae/Marchantiaceae

79

tinues growth), sessile, mostly in single groups, ±

4 mm wide; carpocephalum supported on central

core of parenchymatous tissue, on either side 1

(or 2) slightly obliquely held capsules, domed

above, containing elongated air chambers, basal-

ly with cellular filaments, opening via simple air

pores. Involucres continuous with outer layer of

dome on both sides, as deeply purple-stained

extensions partly covering capsules. Sporophyte

with capsule on short seta, globose, ± 1500 pm

diam., wall cells with semi-annular thickenings.

Figure 18. Spores 117.5-142.5 pm diam., polar,

triangular-globular, dark red; distal face rounded,

with 6-8 highly convoluted, raised areas across,

22.5-27.5 pm wide, bordered by superimposed

layers of granules and hollowed in the centre,

distinctly or poorly separated by deep furrows;

proximal face with triradiate mark absent, but

with slight flattening of 3 facets, entirely encrust-

ed with numerous, tiny granules, wing absent,

margin scalloped by projecting convoluted areas

from distal face. Elaters brownish red, tapering

slightly at one end, blunt and thicker at the other,

70-90 x 20 pm, unispiral or ringed. Chromo-

some number, n = 18, 32 (T. Bomefeld pers.

comm, via O.H. Volk). Plate 8D-F.

Exormotheca holstii is known from the fol-

lowing African countries, Tanzania ( locus clas-

sics), Zimbabwe (Best 1990) and southern

Africa, where it has been reported from

Namibia — several collections recorded by Volk

(1979) — Botswana, North-West, Northern Pro-

vince, Gauteng, Mpumalanga, Free State and

KwaZulu-Natal. Map 7.

It is found mainly on quite dry, somewhat

sandy or gravelly soil, sometimes between grass

or in exposed areas that are only occasionally

wet and that overlie sandstone or quartzitic or

granitic rock. It sometimes grows in association

with Riccia species, such as R. volkii, R. rosea

and R. albovestita.

Exormotheca holstii can be distinguished

from other species in the genus by its large size,

its tall air chambers, basal V5 — ‘/3 occupied by

chlorophyllose filaments, and laterally adjoined

except for the apical 250 pm toward the centre

of the thallus and marginally for the apical ±

500 pm; by the large, hyaline, triangular scales

with long filiform appendages and its subsessile

gynoecia. Tubers were not found.

Vouchers: Bottomley CH3566; M.J.A. W. Cros-

by 1115; Germishuizen 2839; Giess 15383; Glen

2243; Perold 2702; Volk 81/124.

Note: E. bulbigena sp. nov. by Bornefeld et

al. (1996) is not included here, as my treatment

was completed before their paper was published.

MARCHANTIACEAE

Marchantiaceae (Bisch.) Lindl., An introduction to the natural system of botany, edn 2: 26, 412

(1836); Dumort.: 69 (1829), emend. Mull.Frib.: 264 (1940b); Mull.Frib.: 382 (1951-1958); Hassel

de Menendez: 141 (1963); S.W.Arnell: 52 (1963a); R.M.Schust.: 299 (1992c). Type: Marchantia L.

Thalli medium-sized to very large, in crowded mats; green to dark green, sometimes leathery,

rarely translucent. Branches pseudodichotomously furcate, with or without apical and ventrolater-

al innovations, broadly band-shaped or narrowly ribbon-shaped, apex notched, often with median

scale appendages recurved over edge; groove absent, thallus dorsally flat, margins lobulate, crenu-

late or undulate, sparsely hirsute in Dumortiera; flanks sloping very obliquely; ventral face medi-

anly strongly keeled. Scales in 4 or 6(8) rows, 2 or 3(4) on either side of keel, covering part or all

of ventral face, rarely projecting beyond margins; median scales bluntly triangular, constricted

where joined to appendage; laminal scales smaller, lacking appendage; marginal scales rarely pre-

sent; in Dumortiera scales vestigial and evanescent.

Dorsal epidermis often lacking chloroplasts, mostly unistratose, cell walls thin or slightly thick-

ened, without trigones, absent in Dumortiera ; air pores, when present, compound, surrounded by

80

HEPATOPHYTA: March anti ace ae

I

ii\y

HEPATOPHYTA: MARCHANTIACEAE

81

several superimposed concentric rings of cells, some above epidermis, others projecting into air

chambers. Assimilation tissue with shallow air chambers in 1 storey, densely packed with 2 — 4(5)-

celled chlorophyllose filaments, absent in Dumortiera-, storage tissue occupying ventral part of

thallus or almost all of thallus in Dumortiera , compact, sometimes with a few slerotic cells and/or

mucilage cavities; oil cells scattered, these also present elsewhere in thallus and scales.

Asexual reproduction in Marchantia spp. only, by discoid gemmae contained in hollow cupules

borne dorsally on thalli, contracted below, flaring above, margin ciliate, lobed-ciliate, dentate or

nearly entire.

Monoicous or dioicous (in Marchantia spp.). Antheridiophore with stalk fairly long in

Marchantia spp., very short in Dumortiera , disc lobed or divided into rays in Marchantia spp.,

unlobed in Dumortiera, antheridia sunken in dorsal side, air pores present only in Marchantia spp.,

ventral side with several rows of scales. Stalk usually with 2 rhizoid furrows, air chambers present

in Marchantia spp., absent in Dumortiera. Arche goniophore with carpocephalum convex above,

lobed or divided into rays, dorsally with compound air pores in Marchantia spp., absent in

Dumortiera, below with scales and sporophytes in groups, alternating with lobes or rays (in African

Marchantia species). Stalk basally sometimes surrounded by large scales, generally without

appendage, along its length bearing filiform scales, 2-4 rhizoid furrows and 0-2 bands of air cham-

bers. Involucre bivalved, membranous in Marchantia spp., fleshy and saccate in Dumortiera.

Pseudoperianths present in Marchantia spp., membranous and delicate, bell-shaped, enclosing

sporophytes individually, absent in Dumortiera. Sporophyte with foot, short seta and subglobose to

ovoid capsule, wall unistratose, with annular thickenings, dehiscing irregularly in Marchantia spp.

or by valves in Dumortiera. Spores small, thin-walled, ± triangular-globular, ornamentation with

numerous thin, irregularly convoluted ridges or with few wide ridges separated by granules, the 2

faces similar or dissimilar in Marchantia spp., ornamented with nodules in Dumortiera. Elaters

tapering at ends, bi- or trispiral. Chromosome number : n = 9 (basically).

Five genera, Marchantia L., Dumortiera Nees, Preissia Corda, Bucegia Radian and Neohodg-

sonia H.Perss. are classified in the family Marchantiaceae, but only the first two are found in south-

ern Africa. Each one of the two locally occurring genera has been placed in its own subfamily:

Marchantia (and extra-territorial Preissia) in Marchantioideae and Dumortiera in Dumor-

tieroideae; Bucegia and Neohodgsonia have been referred to the subfamily Bucegioideae.

Key to local subfamilies of Marchantiaceae

Air pores of thallus compound; epidermis and air chambers present; thallus margins not

hirsute; male receptacles on long stalks; cupules bearing gemmae present

Marchantioideae

Air pores, epidermis and air chambers of thallus absent; thallus margins hirsute; male re-

ceptacles on very short stalks; cupules absent Dumortieroideae

Figure 18. — Exormotheca holstii. A-C, thallus: A, with sessile carpocephalum from above; B, with antheridial necks

emerging in midline between air chambers; C, c/s showing tall air chambers, chlorophyllose cell filaments and storage tis-

sue. D, air pore and surrounding cells from above; E, top part of 2 partly adjoining air chambers; F, assimilation tissue with

cell filaments; G, scale with branched filiform appendages; H, carpocephalum, upper half three-dimensional, lower half in

c/s. I, J, capsule wall: 1, from above; J, cross section. K, c/s of seta. A, H, K, Germishuizen 2839\ C, Perold & Koekemoer

2872\ D, Perold 2702', E, F, Glen 2190', G, I, J, Holst 3107. Scale bars: A-C, H, 1 mm; D-F, I-K, 100 pm; G, 500 pm.

Drawings by A. Pienaar.

82

HEPATOPHYTA: MARCHANTIACEAE

Subfamily MARCHANTIOIDEAE (excluding Preissia)

Type: Marchantia L.

Thalli medium-sized to large, in crowded mats; green, sometimes leathery. Branches pseudodi-

chotomously furcate, without innovations, broadly band-shaped or narrowly ribbon-shaped, apex

notched, median scale appendages recurved over edge; groove absent, thallus dorsally flat, margins

lobulate, crenulate or undulate, sometimes purplish; flanks sloping very obliquely; ventral face

medianly strongly keeled. Scales in 4 or 6 rows, covering part or all of ventral face, rarely pro-

jecting beyond margins.

Dorsal epidermis often hyaline, mostly unistratose, cell walls thin or slightly thickened, with-

out trigones; air pores compound, surrounded by several superimposed, concentric cell rings, cells

of inner opening sometimes covered with black granular deposit. Assimilation tissue with one

storey of shallow air chambers, densely packed with chlorophyllose filaments; storage tissue some-

times with a few sclerotic cells and/or mucilage cavities; oil cells scattered throughout thallus.

Asexual reproduction by discoid gemmae.

Dioicous. Antheridiophore with receptacle lobed or divided into rays. Stalk with 2 rhizoid fur-

rows and 0-2 bands of air chambers. Arche goniophore with carpocephalum lobed or divided into

rays. Stalk with 2-4 rhizoid furrows and 0-2 bands of air chambers, basally sometimes surround-

ed by large scales. Involucre bivalved, membranous. Pseudoperianth membranous, bell-shaped.

Sporophyte with subglobose capsule, dehiscing irregularly. Spores ± triangular-globular, orna-

mented with thin, irregularly convoluted ridges or with wide ridges and granules between. Elaters

bi- or trispiral. Chromosome number, n = 9 (basically).

MARCHANTIA

Marchantia L., Species plantarum, edn 1: 1137 (1753) emend. Raddi, Opuscoli scientifici,

Bologna: 358 (1818); Sim: 27 (1926); S.W.Arnell: 53 (1963a); Bischl.: 6 (1984); Bischl.: 13

(1989a); Bischl.: 13 (1993); R.M.Schust.: 305 (1992c); Perold: 183 (1995c). Type: Marchantia

polymorpha L. [lecto. fide Leman: 115 (1823)].

Marchantiopsis Douin & R.C.V.Douin: 135 (1918).

Chlamidium Corda in Opiz: 647 (1829).

The generic diagnosis is contained in the diagnosis of the subfamily.

The genus is subdivided into three subgenera: Marchantia , Chlamidium (Corda) Bischl. and

Protomarchantia R.M.Schust. on the basis of differences in, inter alia, spore morphology, germi-

nation patterns and flavonoid patterns. Protomarchantia is absent from our region.

Key to local subgenera, sections and species of Marchantia

la Phalli with margins plicate-crisped, crenulate or lobulate; dorsally with or without dark

median band; cells bordering inner opening of epidermal air pores with slightly or

strongly projecting walls, pores then cruciate; scales in 4-6 rows, covering 3A» or all of

ventral surface, then also extending beyond margins; appendages of median scales

orbicular or reniform or ovate, marginal cells slightly or strikingly smaller than inner

cells; laminal scales much wider than long; cupule margins with ciliate lobes, exter-

HEPATOPHYTA: Marchantiaceae

83

nally with papillae; male receptacles peltate, shallowly dissected into 6-10 broad

lobes; membranous margins of rays crenulate or entire, then with very small cells;

female receptacles deeply dissected into 9-11 terete rays, with or without papillae;

stalks with single broad band of air chambers; involucre margins with ciliate lobes;

spores 8-16 pm diam., ornamentation on 2 faces similar, with numerous narrow, con-

voluted ridges . . . subgenus Marchantia (p. 84):

2a Thalli with margins entire or crenulate; dorsally often with dark median band; cells bor-

dering inner opening of epidermal pores with slightly convex inner walls, pores not

cruciate; ventral scales in 6 rows, extending beyond thallus margins; median scale

appendage small, margins bordered with somewhat smaller cells; membranous margin

of male receptacle crenulate, with slightly smaller cells; rays of female receptacle with

numerous papillae 1 . M. polymorpha

2b Thalli with margins lobulate; dorsally without dark median band; cells bordering inner

opening of epidermal pores with strongly convex inner walls, pores cruciate; ventral

scales in 4(-6) rows, not extending beyond thallus margins, marginal scales some-

times partly or altogether absent; median scale appendage large, margins entire or

slightly crenulate, bordered with strikingly small marginal cells; membranous margin

of male receptacle not distinctly crenulate, composed of very small cells; rays of

female receptacle without papillae 2. M. berteroana

lb Thalli with margins entire, nearly flat or sometimes slightly undulate; dorsally with or

without dark median band; cells bordering inner opening of epidermal pores with

straight or convex walls, rarely with strongly projecting processes, pores then cruciate;

scales in 4 rows, covering 'A to almost 2A of ventral surface; median scale appendage

orbicular, ovate or ± triangular, apically acuminate, acute or apiculate, marginal cells

rather smaller than inner ones; laminal scales as long as or longer than wide; cupule

margins ciliate, almost entire or rarely with ciliate lobes, externally rarely with papillae;

male receptacles palmate or rarely peltate, shallowly or deeply dissected into rays;

membranous margin of rays entire or slightly crenulate; female receptacles dissected

into 5-9 apically ± flat lobes; stalks with air chambers in 1 or 2 bands; involucre mar-

gins ciliate or entire, rarely with ciliate lobes; spores 20-35 pm diam., ornamentation on

2 faces dissimilar, distally mostly with wide ridges . . . subgenus Chlamidium (p. 92):

3a Thalli medium-sized to large, 6 — 8(— 1 1 ) mm wide; cells bordering inner opening of epi-

dermal pores with strongly projecting walls, pores cruciate; median scale appendages

with margins entire or slightly denticulate; cupule margins with triangular, ciliate

lobes, externally with numerous papillae; female receptacle deeply dissected into

lobes, apically truncate or emarginate; involucre margins with ciliate lobes . . . sec-

tion Paleaceae (p. 92) 3. M. paleacea

3b Thalli smallish to large, 3.5-10.0 mm wide; cells bordering inner opening of epider-

mal pores with straight or convex walls; median scale appendages with margins

often distinctly toothed; cupule margins with long or short cilia or almost entire,

externally without or with few papillae; female receptacle shallowly or deeply dis-

sected into lobes; involucre margins ciliate or ± entire:

4a Thalli 6.0-8. 5(-l 0.0) mm wide; dorsally without dark median band; median scale

appendages large, inner cell structure ‘loose’ with large cells; cupule margins with

cilia up to 6 cells long; female receptacle large, shallowly dissected into broad

lobes, sometimes bearing a male ray; involucre margins ciliate . . . section Chlami-

dium (p. 95) 4. M. pappeana

84

HEPATOPHYTA: Marchantiaceae

4b Thalli 3. 0-7. 5 mm wide; mostly with distinct dark median band dorsally; median

scale appendages small, inner cells not markedly large and structure not ‘loose’;

cupule margins crenulate or with short cilia, up to 3 cells long; female receptacle

rather small, deeply dissected into narrow lobes; involucre margins entire or

crenulate . . . section Papillatae (p. 99) 5. M. debilis

Subgenus Marchantia

Marchantia L. sect. Astromarchantia Nees: 60, 61 (1838) (nom. illegit.).

Marchantia L. (without rank) Stellatae Gottsche et al.: 522 (1844-1847, published 1846).

Marchantia L. (without rank) Marchantiotypus Dumort.: 150 (1874).

Thalli with wide branches, from nearly 7 mm to almost twice that; margins crenulate, lobulate

or plicate-crisped. Scales in 4-6(-8) rows, covering 1 * 3A to all of ventral face: median scale

appendages ovate, orbicular or reniform, not acuminate at apex, margins crenulate, toothed or

entire, sometimes cells in outer row very much smaller than inner ones; laminal scales wider than

long, apically rounded, lacking papillae, upper cell walls with trigones; marginal scales sometimes

present, projecting beyond thallus margins or not.

Dorsal epidermis with or without papillae; air pores surrounded by 4-5(6) concentric rings of

cells, at inner openings sometimes with rounded walls, otherwise with pronounced processes, pores

then cruciate; storage tissue lacking sclerotic cells.

Cupule margins with acutely triangular, toothed lobes, externally papillate.

Dioicous. Antheridiophores with receptacles ± symmetrical, peltate, rays very short and broad.

Archegoniophores with receptacle deeply dissected into terete lobes. Stalks of gametangiophores

with 2 rhizoid furrows. Involucre margins toothed or ciliate. Spores small, 8-16 pm diam.; 2 faces

similarly ornamented, with numerous thin, highly convoluted ridges, triradiate mark on proximal

face distinct to absent, wing absent.

Marchantia polymorpha (with three subspecies), M. berteroana and M. plicata (from central

and South America) are classified in subgenus Marchantia.

1. Marchantia polymorpha L., Species

plantarum, edn 1: 1137 (1753); Bischl.: 34

(1993); Perold: 185 (1995c). Type: Europe,

Dill.: t. 76, fig. 6E, F (1741) [OXF, lecto., typo.,

fide Bischl. & Boisselier-Dubayle: 363 (1991)

(photo, of typo, in PRE!)].

Synonymy see Bischl. (1993).

Thalli large, in crowded patches; bright, yel-

lowish or deep green, medianly with or without

dark band, areolate, air pores small to large,

margins reddish brown, crisped, entire, some-

times crenulate; when dry, margins not raised.

Branches prostrate to somewhat erect, repeated-

ly pseudodichotomously furcate, broadly obo-

vate, total length up to 35 mm, 7-10 mm wide,

325-375 um thick medianly, in section 21-27

times wider than thick, apex notched, median

scale appendages recurved over edge; groove

absent, thallus margins acute, thin; flanks slop-

ing obliquely; ventral face medianly keeled.

Scales in 6 rows, entirely covering ventral face

and extending beyond thallus margins: median

scales closest to keel, with body obliquely tri-

angular, pale mauve, up to 750 pm long, base

1575-2250 pm wide, narrowed above and

deeply constricted where joined with append-

age, oil cells sparsely scattered throughout

HEPATOPHYTA: Marchantiaceae

85

scale, appendage of median scale broadly

rounded, brown or purple, (350-)400-640 x

500-700 pm, margins toothed, crenulate or

almost entire, bordered by slightly smaller cells;

laminal scales lateral to median scales, wedge-

shaped, much wider than long, hyaline or pale

mauve, 600-825 pm long, apex rounded, mar-

gin papillate, base flatly arched, 1450-1750 pm

wide, oil cells rare; marginal scales usually pro-

jecting beyond thallus margins, oblong or ovate,

hyaline or brownish, 700-750 pm long, apex

rounded, base 550-650 pm wide, with 5 or 6

scattered oil cells.

Dorsal epidermal cells unistratose, mostly

hyaline, 4-6-sided, 35-74 x 18-30 pm, thin-

walled, lacking trigones; air pores raised, com-

pound, 30.0-62.5 x 40.0-60.0 pm, surrounded

by (3)4 or 5 concentric rings of 4—6 cells in

each, 2 or 3 above epidermis and 2(3) project-

ing into air chambers, inner opening mostly sur-

rounded by 4 cells protruding into cavity.

Assimilation tissue 50-100 pm thick, air cham-

bers in one storey, containing densely chloro-

phyllose, mostly 3-celled filaments, bounding

walls without chloroplasts; storage tissue with ±

11 rows of cells medianly, decreasing laterally,

sclerotic cells and mucilage cavities absent; oil

cells scattered throughout tissues.

Cupule margins with ciliate, triangular lobes,

cilia at apex of lobes vertical, up to 5 or 6 cells

long, basally on either side transverse; cupule

wall lower down, several cell layers thick, exte-

riorly with numerous 1 -3-celled papillae.

Dioicous. Antheridiophore arising from apex

of terminal segment of main or short lateral

branch, raised on stalk; receptacle ± 8 mm

diam., shallowly dissected into 8(— 10) lobes, ±

375 pm long, symmetric, basal sinus up to 30°

wide, lobe margins membranous, hyaline,

crenulate, cells small in outer 1 or 2 rows; medi-

an scales on ventral side of lobes hyaline,

oblong, with rounded apex, lacking appendage,

1375-1575 x 600-850 pm, margins toward base

sometimes with small papillae, 4-10 oil cells

present. Stalk ± 4.5-15.0 mm long, 975-1000

pm diam., with 2 rhizoid furrows, air chambers

absent; scales at base of stalk large, 1250-2000

x 800 pm, round or oblong, lacking appendage,

bases purple, sometimes with protruding papil-

lae, up to 8 scattered oil cells present; scales

along length of stalk hyaline, filiform, ( 1 )2-3

cells wide. Archegoniophore arising from apex

of terminal segment of main or short lateral

branch, raised on stalk; carpocephalum 9.5-10.0

mm diam., nearly symmetric, with small round

projection dorsally, deeply divided into 9-11

rays, 2. 5-3. 2 mm long, basal sinus ± 40°, mar-

gins distally incurved and terete in cross section,

toward apices with numerous conical papillae;

scales of carpocephalum hyaline, up to 2000 pm

long, 80 pm wide at base, sometimes branched

along length. Stalk 17-40 mm long, 600-1250

pm diam., with 2 rhizoid furrows, 1 band of air

chambers; scales at base of stalk large, 750 x

1000(— 1 750) pm, shape irregular, mostly with-

out appendage, purple or brown or hyaline, lat-

eral margins sometimes with papillae; scales

along length of stalk hyaline or brown, filiform,

2 cells wide. Involucre with margins hyaline or

occasionally purple-tinged, with tapering, ciliate

lobes, 300-350 pm long, 90-150 pm wide at

base, cilia ( 1— )2 — 5 cells long. Sporophyte with

short seta, capsule subglobose, wall dehiscing

by irregular slits. Figure 19. Spores 10.0-12.5

pm diam., triangular-globular, yellow; distal

face with numerous highly convoluted and

branched, smooth ridges; proximal face with

faint, collapsed triradiate mark, facets finely and

densely granular, narrowly winged. Elaters yel-

low-brown, 350-435 pm long, 5 pm wide, grad-

ually tapering to narrow tips, bispiral. Chro-

mosome number: n = 9 (Bischler-Causse 1993a).

Plate 9A, B.

Marchantia polymorpha is widespread and

is known from Europe, Russia, Japan, China,

India and the Americas. It has frequently been

described, but its taxonomy was unresolved

because proper lectotypification had not been

done.

Lectotypification of M. polymorpha was

recently done by Bischler-Causse & Boisselier-

Dubayle (1991) who used a Dillenian illustra-

tion and a specimen held in OXF (i.e. a typo-

type). This corresponds to the first of three

Linnean varieties, namely var. fa], which was

HEPATOPHYTA: MARCHANTIACEAE

87

later called ‘ aquatica' . This first variety [a]

forms the basis for the application of the specif-

ic name (Isoviita 1970). However, since the lec-

totype of M. polymorpha var. polymorpha of

Linnaeus corresponds to the taxon ‘ aquatica ’ (at

any rank), it renders that name illegitimate,

because the epithet ‘ polymorpha ’ would be used

for a taxon not including its type. The best pro-

cedure seemed, therefore, for Bischler-Causse &

Boisselier-Dubayle to describe their three newly

separated electrophoretic groups (in three

enzyme systems: esterases, peroxidases and acid

phosphatases) as subspecies, give two of them

new names and select good, recent type speci-

mens. Marchantia polymorpha L. subsp. poly-

morpha thus corresponds to the taxon formerly

called ‘ aquatica ’ ; M. polymorpha L. subsp. rude-

ralis Bischl. & Boisselier corresponds roughly

to the former ‘ polymorpha sensu stricto' and M.

polymorpha L. subsp. montivagans Bischl. &

Boisselier roughly to the former 'alpestris' .

Specimens recently collected in Gauteng

(Map 8) are clearly introduced. They have been

referred to M. polymorpha subsp. ruderalis

Bischl. & Boisselier, since they grow as weeds

in man-made habitats (nurseries) and agree in

other respects with this subspecies, as distin-

guished by Bischler-Causse & Boisselier-

Dubayle (1991).

Arnell (1963a) reported the species from

southern Africa, namely Golden Gate, near

Clarens in the eastern Free State and from

Zimbabwe (Southern Rhodesia), near Odnazi

River Bridge, Umtali. These specimens are not

held at PRE or at BOL and up to now, the nat-

ural presence here of M. polymorpha has not

been confirmed.

Typical characters of the subspecies: fresh

thalli prostrate and bright green, with a dark,

rather indistinct and discontinuous median band

with elongated air chambers; dorsal air pores

50.0-62.5 pm wide, dorsal epidermal cells

35-55 pm long and median scale appendages,

350-500 x 510-760 pm, with toothed margins.

Marchantia polymorpha is very similar to M.

berteroana , but can be distinguished from it by

the marginal scales which are always present

and which mostly extend beyond the crisped,

sometimes crenulate thallus margins, by the air

pores not being cruciate, by the presence of

numerous papillae on the rays of the female

receptacle and by the appendages of the median

scales bordered by larger cells.

Vouchers: Glen 3468, 3728.

2. Marchantia berteroana Lehm. &

Lindenb. in Lehm., Novarum et minus cogni-

tarum stirpium, pugillus 6: 21 (1834); Gottsche

et al.: 481 (1844-1847); Steph.: 393 (1898,

1899, 1900); Schiffn.: 41-44 (1896); A.Evans:

246 (1917); Hassel de Menendez: 160 (1963);

S.W.Arnell: 55 (1963a); E.O.Campb.: 122

(1965); Bischl.: 44 (1984); Bischl.: 81 (1989a);

Bischl.: 56 (1993); Perold: 189 (1995c). Type:

‘in insula Juan Fernandez legit cl. Bertero

(Herb. Hookeri)’ ( W8294 , holo.; FH, G, NY,

PC, STR, W, iso.).

M. tabularis Nees: 71 (1838); Sim: 28 (1926). Type:

South Africa, Tafelberg, [leg. Ecklon W82891 (female),

syn.; leg. Bergius (male) STR, syn.].

M. contractu Bisch.: 135 (1846) fide Bischl. (1993a).

Type: South Africa, Cap, Duyvelsberg, Krauss s.n. (BM,

FH, G!, PC, W).

Figure 19. — Marchantia polymorpha subsp. ruderalis. A-C, thallus: A, dorsal face of male with antheri-

diophore and cupule; B, ventral face; C, cross section. D-F, air pore: D, from above; E, from below; F, c/s with dor-

sal epidermal cells and air chamber. G, margin of thallus; H, cupule margin; 1, marginal scale; J, laminal scale; K,

median scale; L, appendage of median scale; M, male receptacle; N, female receptacle from side; O, c/s of male stalk;

P, c/s of female stalk; Q, median scale of male receptacle; R, scale from along male stalk; S, scale from female recep-

tacle; T, scale from along female stalk; Ui, U2, scales from foot of male stalk; Vi, V2, scales from foot of female stalk;

W, c/s of female ray; X, part of section of female ray, showing papillae on epidermal cells and air chambers; Y, mar-

gin of male ray; Z, margin of involucre. A, M, O, Q, R, Ui, U2, Y, Perold & Koekemoer 3248\ B-L, N, P, S, T, Vi, V2,

W|, X, Z, Glen 3728. Scale bars: A, B, M, N, 2 mm; C, 1 mm; D-F, 50 pm; G, X, Y, 100 pm; H-L, O-W, 250 pm.

Drawings by M. Steyn.

HEPATOPHYTA: March anti aceae

Plate 9.— Spores. A, B, Marchantia polymorpha: A, distal face; B, proximal face. C, D, M. berteroana: C, dis-

tal face; D, proximal face. E, F, M. pappeana: E, distal face; F, proximal face. A, B, Perold & Koekemoer 3249\ C, D,

Geldenhuys 1332, E, F, H. Anderson CH13278. A, B, x 3900; C, x 3950; D, x 3720; E, x 1580; F, x 1540.

HEPATOPHYTA: Marchantiaceae

89

Thalli robust, in crowded, overlying mats;

green, yellowish green or bluish green, almost

leathery, without distinct median band, faintly

areolate, air pores numerous, small, almost

closed, margins hyaline, purplish or brownish,

irregularly lobulate, ± plicate but not crisped,

entire or minutely crenulate; when dry, margins

not raised. Branches repeatedly furcate, but

rather irregularly so, terminal segments broadly

oblong, up to 20 mm long, 9.5-1 2.0(-l 5.0) mm

wide, 600-900 pm thick medianly, in section

13-16 times wider than thick, apex notched,

median scale appendages recurved over edge;

groove absent, thallus dorsally rather flat, mar-

gins acute, thin, slightly recurved; flanks slop-

ing obliquely; ventral face medianly keeled,

brownish or purplish. Scales in 4 (sometimes 6)

ventral rows, extending over 3A— y/io of thallus

width, but mostly not right up to margin: medi-

an scales with body obliquely triangular, hya-

line or purplish, up to 1450 pm long, base hard-

ly arched, 2875-3500 pm wide, gradually nar-

rowing upwards, abruptly and deeply constrict-

ed where joined with appendage, ± 35 oil cells

scattered throughout, appendage of median

scales orbicular to broadly ovate, brownish,

hyaline or purplish or both, 675-950 x 650-800

pm, apex rounded to somewhat obtusely nar-

rowed, basally cordate, margins entire or

minutely crenulate, bordered by 1 or 2(3) rows

of cells very much smaller than inner ones; lam-

inal scales lateral to, and alternating irregularly

with median scales, broadly rounded, mostly

hyaline, yellowish brown or reddish, 850-1125

pm long, base flatly arched, 1875-3375 pm

wide, much wider than long, margins entire or

slightly crenulate, ± 12 scattered oil cells pre-

sent; marginal scales rarely to sometimes pre-

sent, when ± scattered and not extending to

thallus margins, crescent-shaped with rounded

apex, hyaline, 675-1250 x 775 pm.

Dorsal epidermal cells mostly unistratose,

hyaline, polygonal, (50-)57.5-77.5 x 20.0-30.0

pm, walls slightly thickened; air pores raised,

compound (37.5-)57.5-75.0 x 27.5-47.5(-55.0)

pm, surrounded by (4)5-7 concentric rings of 3

or 4 cells in each, 3(4) above epidermis and 3 or

4 projecting into air chambers, inner opening

mostly with 4 or 5 cells, inside walls strongly

protuberant, leaving only a small, usually cruci-

ate opening. Assimilation tissue 45-50(-60) pm

thick, air chambers in one storey, containing

densely chlorophyllose filaments, bounding

walls 3 or 4 cells high; storage tissue occupying

most of ventral part of thallus medianly,

decreasing laterally, cells containing scattered

starch grains, but sclerotic cells and mucilage

cavities absent; oil cells scattered throughout

tissues.

Cupule margins with ciliate, ± triangular

lobes, cilia at apex of lobes vertical, 10 or 11

cells long, basally on either side transverse,

(2— )3 or 4-(-6)-celled; cupule wall lower down,

several cell layers thick, exteriorly with numer-

ous 1 or 2(-3)-celled papillae.

Dioicous. Antheridiophore arising from apex

of terminal segment of main or short lateral

branch, raised on stalk; receptacle up to 10 mm

diam., shallowly dissected into 8(9) ± symmet-

ric lobes, basal sinus ± 80° wide, lobe margins

membranous, brownish or hyaline, minutely

crenulate, with 1 or 2 rows of very small cells;

median scales on ventral side of lobes hyaline,

750-1375 x 1000-1875 pm, appendage absent

or present, ± 267.5 x 200.0 pm, oblong, round-

ed apically, not or hardly constricted at join with

scale. Stalk 23-30 mm long, ± 1000 pm diam.,

with 2 rhizoid furrows, air chambers absent;

scales at base of stalk large, up to 1200 x 1400

pm, roughly triangular or oblong, lacking an

appendage, hyaline or purplish, along upper

margins 1 or 2 rows of very small cells, ± 10 oil

cells scattered throughout; scales along length

of stalk hyaline, filiform, 3-9 cells wide.

Arche goniophore arising from apex of terminal

segment of main or short lateral branch, raised

on stalk; carpocephalum up to 10 mm diam.,

nearly symmetric, dorsally with small round

median projection, deeply divided into 9 linear

rays, up to 2.6 mm long, basal sinus ± 45° wide,

margins distally slightly incurved, terete in

cross section, lacking papillae toward apex;

scales of carpocephalum hyaline, filiform, up to

2150 pm long, 35.0-87.5 pm wide at base,

often splitting further along and strands mostly

90

HEPATOPHYTA: Marchantiaceae

HEPATOPHYTA: Marchantiaceae

91

only 2 cells wide. Stalk 48-65 mm long, up to

1000 pm diam., with single band of air cham-

bers and 2 rhizoid furrows; scales at base of

stalk oblong or ovate, without appendage, apex

rounded, brownish or hyaline, large, 1575-2000

x 800-1250 pm, margins apically occasionally

slightly crenulate, with very small cells; scales

along length of stalk hyaline, filiform, up to

6500 pm long, 2 or 3(4) cells wide. Involucre

with margins hyaline or purplish, with tapering,

ciliate lobes, 100-175 pm long, 125-180 pm

wide at base, cilia apically and at sides numer-

ous, tapering, branched and intertwined, up to

220 pm long. Figure 20. Spores 7.5-12.5 pm

diam., ± globular, brownish; distal face with

numerous, much convoluted and branched

ridges; proximal face with faint triradiate mark,

winged and densely covered with numerous

fine granules and tiny irregular ridges. Elaters

yellow-brown, (550-)600-640(-770) pm long,

5 pm wide, gradually tapering at both ends for

150-200 pm, bispiral. Chromosome number: n

= 9 (Bischler-Causse 1993). Plate 9C, D.

The species is widely distributed in the

southern hemisphere, from South America,

south to the Antarctic Peninsula and north to

Costa Rica, islands of the Atlantic and south

Indian Ocean, southern Africa, Australia, Tas-

mania, New Zealand, New Guinea, New Cale-

donia, Java and Sulawesi (Bischler-Causse

1993). In southern Africa it is known from

Northern Province, Mpumalanga and from

KwaZulu-Natal, which receive summer rain,

also from Western and southwestern Eastern

Cape, which receive winter rain. Exact locali-

ties of two of the collections by Wilms and by

McLea are not known and a question mark pre-

cedes the symbol on the map. Map 8.

Map 8. — • Marchantia polymorpha subsp. ruderalis

▲ M. berteroana

■ M. paleacea

Marchantia berteroana generally grows on

damp soil, and sometimes on wet rocks, at

stream banks, near waterfalls, along paths, in

kloofs, passes, ravines, gorges, in forests under

trees or in burnt-over areas.

Specimens of M. berteroana are easily dis-

tinguished by the tiny marginal cells of the

median scale appendages, by the cruciate dorsal

pores and by the lobulate thallus margins. The

membranous margins of the rays of the male

receptacle also have very small cells. Otherwise

it is quite similar to M. polymorpha, except for

the latter having papillae on the rays of the car-

pocephalum. The ornamentation of their spores

is also quite similar.

Vouchers: Arnell 1058 (BOL); Barnard

CHI 3 15; Bolus CH1319; Duthie CHI 320; Gar-

side 6185.

Figure 20. — Marchantia berteroana. A-C, thallus: A, dorsal face with cupule; B, ventral face; C, cross section. D-F,

air pore: D, from above; Ei, E2, from below; F, c/s with dorsal epidermal cells and air chamber. G, margin of thallus; H,

laminal scale; I, median scale; Ji, J2, appendages of median scales; K, cupule margin; L, female receptacle; M, male recep-

tacle; N, c/s of male stalk; O, c/s of female stalk: P, scale from foot of male stalk; Q, scale from along male stalk; R, medi-

an scale of male receptacle; S, margin of male ray; T, scale from foot of female stalk; U, scale from female receptacle; V,

margin of involucre. A, F, G, L, N, P, R, S, A.E. van Wyk 2066: B-Ei, E2, H-Ji, J2, M, O, T-V, Geldenhuys 1332 ; K, Q,

Pillans 4048. Scale bars: A, B, L, M, 2 mm; C, 1 mm; D-G, 50 pm; H-K, N-R, T, 250 pm; S, U, 100 pm. Drawings by

M. Steyn.

92

HEPATOPHYTA: MARCHANTIACEAE

Subgenus Chlamidium

Subgenus Chlamidium (Corda) Bischl. in Cryptogamie, Bryologie et Lichenologie 3: 362 (1982);

Bischl.: 89 (1989a); Bischl.: 65 (1993); Perold: 192 (1995c). Type: Chlamidium indicum Corda

(‘Sieber flora mart, exsicc. No. 375’) = Marchantia chenopoda L. Type: Sieber 378 p.p. [W, neo.;

STR, iso., fide Bischl. (1984)].

Chlamidium Corda in Opiz: 647 (1829).

Marchantia L. sect. Chlamidium (Corda) Nees: 60, 101 (1838).

Thalli with branches rather narrow, ± 2.4 mm wide to 4 times that; margins nearly flat, entire,

sometimes slightly undulate, rarely crisped. Scales in 4 rows, covering '/4 to 2/3 of ventral face, oil

cells present or absent: median scales with appendages variously shaped, orbicular, ovate or trian-

gular, apically often acuminate, acute or apiculate, seldom rounded, margins entire, crenulate-ser-

rate, coarsely toothed or lobed; laminal scales as long as, or longer than wide, sometimes in 2

incomplete rows on either side of median scales, apically acute or obtuse, with papillae, upper cell

walls lacking trigones.

Dorsal epidermis without papillae; air pores surrounded by (4)5-7 concentric rings of cells, at

inner openings with straight or convex walls, rarely with pronounced, rounded processes and pores

then cruciate; storage tissue often with scattered sclerotic cells.

Cupules with margins ciliate, almost entire, or with ciliate lobes, externally without, or rarely

with papillae.

Dioicous. Antheridiophores with receptacle symmetric or asymmetric, palmate or rarely peltate,

rays shallowly or deeply dissected. Arche goniophores with receptacle symmetric, or sometimes

asymmetric, dissected into 5-9 rays, flat or convex but never terete; scales of receptacle in African

species apically with marginal cells rectangular and long axis parallel to margins. Stalks of

gametangiophores with 2 (-4) rhizoid furrows. Involucre with margins ciliate or crenulate to entire,

rarely with ciliate lobes. Spores larger than in subgenus Marchantia, 20-35 pm diam.; distal face

generally ornamented with thick ridges separated by dense granules; proximal face with coarse

granules only, triradiate mark and thick wing usually present.

Subgenus Chlamidium contains three sections, Paleaceae, Chlamidium and Papillatae. All three

are represented in southern Africa by a single species.

Subgenus Chlamidium section Paleaceae Bischl. in Bryophytorum Bibliotheca 38: 90 (1989a);

Bischl.: 67 (1993); Perold: 192 (1995c). Type: M. paleacea Bertol. [lecto. fide Grolle: 210 (1976)].

Thalli with branches (3.5— )6.0— 8.0(— 1 1 .0) mm wide, irregularly spaced, narrowly divergent;

median scales with appendage oblong, ovate or suborbicular, apically rounded, acute or shortly

apiculate, basally cordate, width across broadest part 650-750 pm, margins entire, crenulate or

slightly denticulate.

Dorsal epidermis without papillae; air pores with inner opening cruciate, inside walls of bor-

dering cells strongly protuberant.

Cupules with margins triangularly lobed and ciliate, externally with 1- or 2-celled papillae.

HEPATOPHYTA: Marchantiaceae

93

Dioicous. Antheridiophore with receptacle peltate, shallowly dissected into 6-10 broad,

rounded lobes, dorsal surface lacking papillae. Archegoniophore with receptacle bearing promi-

nent median projection dorsally, deeply divided into 8 or more convex lobes, basally costate, api-

cally truncate or hardly broadened, emarginate. Stalks of gametangiophores basally surrounded

by large scales. Involucre margin with ciliate lobes. Spores 19-25 pm diam.; ornamentation on

distal face lacking alveoli, mostly covered with a rather featureless, granular layer or with very

irregular ridges, broken up or folded in or convoluted; proximal face different, thickly winged,

triradiate mark faint, covered with dense granules or centrally with narrow, irregular granular

ridges.

Only the two subspecies of M. paleacea belong to this section. The ornamentation of the

spores is distinctive. Additional differences from the other two sections in subgenus Chlamidium

are the shape of the female receptacle and the ciliate, lobed margins of the involucres and

cupules.

3. Marchantia paleacea Bertol. in Opus-

coli scientifici. Bologna 1: 242 (1817); Bischl.:

55 (1984); Bischl.: 91 (1989a); Bischl.: 68

(1993); Perold: 193 (1995c). Type: Italy, Bor-

gonuovo secus valles in Liguria orientali, D.

Turio, 1810 [BOLO, lecto. fide Grolle (1976)].

M. papillata Raddi var. italica Raddi: 20 (1822).

Syntypes: Italy, Contomi di Firenze, Raddi s.n. (BOLO, FH,

FI, G, PC, STR).

For further synonymy see Bischler-Causse (1993).

Thalli medium-sized to large, in crowded

mats; bright green to bluish green, sometimes

blotched with dark red pigmentation, firm,

rather leathery, without dark median band, areo-

late, flecked with numerous white oil bodies,

pores numerous, small, generally closed, mar-

gins mostly deep red or pink, entire, proximally

undulate and scalloped; when dry, margins crin-

kled, not raised or incurved. Branches repeated-

ly furcate, terminal segments oblong, up to 15

mm long, (3.5— )6.0— 8.0(— 1 1.0) mm wide, 750-

800 pm thick medianly, in section ± 8-10 times

wider than thick, apex notched, median scale

appendages recurved over edge; groove absent,

thallus dorsally flat, margins acute; flanks slop-

ing obliquely; ventral face medianly keeled,

dark red entirely or only medianly, the remain-

der green. Scales in 4 ventral rows, extending

over V3 V2 of thallus width: median scales with

body obliquely triangular, mauve, up to 1050

pm long, base arched, ± 3250 pm wide, gradu-

ally narrowing upwards, abruptly and deeply

constricted at join with appendage, up to 25 oil

cells scattered throughout, appendage of medi-

an scales ovate, oblong or suborbicular, margin-

ally orange-brown or purplish, internally pink

or occasionally hyaline, 810-875 x 650-750

pm, apex rounded, acute or shortly apiculate,

basally generally ± cordate, margins entire,

crenulate or slightly denticulate, bordered by 1

row of smaller cells, oil cells absent or 1, 2 or

more present; laminal scales lateral to and alter-

nating irregularly with median scales, asymmet-

rically oblong, mauve or internally mauve and

marginally hyaline, 750-1575 pm long, base

slightly arched or oblique, 500-650 pm wide,

longer than wide, margins entire or slightly

crenulate, up to 10 oil cells present.

Dorsal epidermal cells mostly unistratose,

hyaline, long-rectangular or polygonal, (45. 0-)

60.0-80.0 x 27.5- 37.5 pm, walls thin or slight-

ly thickened; air pores raised, compound, 40.0-

50.0 x 35.0-42.5 pm, surrounded by 4— 6(— 7)

concentric rings of cells, 2 or 3 above epidermis

and up to 4 projecting into air chambers, inner

opening with 4 or 5 cells, inside walls strongly

protuberant, leaving only a small cruciate open-

ing. Assimilation tissue 75-100 pm thick, air

chambers in one storey, containing densely chlo-

rophyllose filaments, bounding walls 3 or 4(5)

cells high; storage tissue occupying most of

ventral part of thallus medianly, decreasing late-

rally, cell walls pitted, central area sometimes

stained purple, sclerotic cells and mucilage cav-

ities absent in specimens seen, but reportedly

HEPATOPHYTA: Marchantiaceae

HEPATOPHYTA: Marchantiaceae

95

sometimes present; oil cells scattered through-

out tissues, numerous in dorsal epidermis.

Cupule margins with ciliate, ± triangular

lobes, cilia at apex of lobes up to 6 vertical cells

long, basally on either side transverse, 1-3(4)-

celled; cupule wall lower down several cell lay-

ers thick, exteriorly with 1- or 2-celled papillae.

Chromosome number : n = 9 (Bischl. 1984, 1988,

1989a). Figure 21.

Only sterile plants are known from southern

Africa. Archegoniophores from a specimen

from Madeira, Tavares s.n., were illustrated in

Perold (1995c: fig. 5L-R). This widespread

species is known from the southern states of the

USA, Mexico and Central America, the Medi-

terranean, northern Yemen, the Caucasus,

Himalayas and the Far East. In Africa (and

islands) it has been collected in Algeria,

Ethiopia, the Azores, Madeira, Cape Verde and

Reunion. In the FSA area it is only known from

Pilgrim’s Rest, Mpumalanga, where it grows on

a steep bank of the Blyde River and from Forest

Falls, near Graskop. Map 8.

M. paleacea subsp. paleacea has been placed

in subgenus Chlamidium on account of the 4

rows of ventral scales restricted to the median

part of the thallus. It differs from other species in

the subgenus by its cruciate epidermal pores,

cupules with ciliate lobes at the margins and

median scale appendages which are ovate to

orbicular. The species is assigned to the mono-

typic section Paleaceae because of the shape of

the female receptacle and the structure of the

margins of the involucres and cupules, which

have ciliate lobes that are externally papillate.

In the Far East, a subspecies, M. paleacea

subsp. diptera (Nees et Mont.) S.Hatt., is recog-

nized (Bischler-Causse 1989a). It is distinguish-

ed from subsp. paleacea by the epidermal pores

of the thallus usually surrounded by 7 or 8 rings

of cells, by the frequent presence of non-func-

tional female receptacles and by the marginal

cells in the median scale appendage with the long

axis oblique to perpendicular to the margins (not

parallel to, as in the typical subspecies).

Vouchers: Perold 3264, 3265\ Perold & Koeke-

moer 4031 .

Subgenus Chlamidium section Chlamidium (Corda) Nees

Thalli with branches (6.0-)7.0-8.5(-10.0) mm wide, generally rather remotely spaced and nar-

rowly divergent; median scales with appendage ovate to orbicular or broadly triangular, apically

rarely obtuse, mostly acute, sometimes shortly apiculate, basally rounded or cordate, width across

broadest part 375-530 pm, margins entire or sometimes bluntly toothed, with 1 or 2 oil cells, rarely

more numerous.

Dorsal epidermis without papillae; air pores with inner opening bordered by cells, their inside

walls convex to nearly straight or with short, rounded processes.

Cupules with ciliate margins, cilia up to 6 or 7 cells long and 3 cells wide basally, externally

sometimes also with several cilia.

Dioicous. Antheridiophore with receptacle palmate, shallowly to deeply dissected into 6-8

(-10) rays, dorsal surface with or without papillae. Arche goniophore with receptacle bearing

Figure 21. — Marchantia paleacea. A-C, thallus: A, dorsal face; B, ventral face; C, cross section D-F, air pore: D,

from above; Ei, E2, from below; F, c/s with dorsal epidermal cells and air chamber. G, margin of thallus; H,. H:, laminal

scales; I, median scale; Ji, J2, appendages of median scales; K, cupule margin; L, female receptacle from side; M, female

receptacle from above; N, c/s of female stalk; O,, 02, scales from foot of female stalk; Pi-Pi, scales from along female stalk;

Qi, Q2, scales from female receptacle; R, margin of involucre. A, Ei, E2, G, I, Ji, J2, Rankin 206, B-D, F, H,, H2, K, Perold

3264 ; L-R, C. Tavares LISU P 66716. Scale bars: A, B, L, M, 2 mm; C, 1 mm; D-G. 50 pm; H-K, N-R, 250 pm. Drawings

by M. Steyn.

96

HEPATOPHYTA: MARCHANTIACEAE

small, median projection dorsally, or not, shortly divided into 9-11 rather flat, short lobes, some-

times basally narrow, widening slightly toward truncate apex. Stalks of gametangiophores basal-

ly surrounded by quite large scales. Involucre margins shortly to longly ciliate. Spores 20-30 pm

diam.; distal face ornamented with wide, irregular, smooth ridges forming incomplete alveoli filled

with nodules; proximal face entirely covered with nodules.

Of the southern African taxa, only M. pappeana belongs in this section. The ornamentation of

its spores is referred to as the chenopoda- type; there are, however, two other spore coat ornamen-

tation types in the section (Bischler-Causse 1989a). The section is distinct in the shape of the

female receptacle and in the ciliate margins of the involucres and cupules.

4. Marchantia pappeana Lelun., Nova-

rum et minus cognitarum stirpium, pugillus X:

21 (1857); Bischl.: 76 (1993); Perold: 197

(1995c). Type: South Africa, ‘In Prom. B.S. leg.

Pappe' , ex herb. Lehmann (RO, holo.?; G! ex

herb. Univ. di Roma).

M. planiloba Steph.: 90 (1886a); Steph.: 181-182

‘153-154’ (1886b). Type: Sao Tome, Cachoeira do Rio

Manuel Jorge, circa S. Nicolau, 800 m, 1885, M oiler 32 [G,

lecto. fide Vanden Berghen: 52 (I960)].

M. wilmsii Steph.: 126 (1892). Type: South Africa,

Transvaal, McLea in Rehmann Hep. austro-afr. exs. 1 [PC,

lecto. fide Vanden Berghen: 44 (1954); BM!, G, NY, S,

isolecto. fide Bischl.: 84 (1993)].

M. parviloba Steph.: 305 (1895b); Vanden Berghen: 46

(1954); S.W.Amell: 56 (1963a). Type: Uganda, Runssoro,

um 2 800 m, 10 Juli 1891, Stuhlmann 2368a [G, lecto. fide

Vanden Berghen: 46 (1954); BM, isolecto. fide Bischl.: 82

(1993)].

M. planiloba Steph. var. walteri Burgeff: 276 (1943).

Type: Tanzania, ‘Nderema in Ost-Usambara, etwa 1 000 m,

leg. H. Walter ’, syn. fide Bischl.: 83 (1993).

M. flavescens Steph. in Bonner: 107 (1953). Type:

Fernando Po, 191 1 Mildbraed 6275 (G).

M. winkleri Steph. in Bonner: 112 (1953). Type:

Cameroon, Winkler 270 (G).

M. stephanii Vanden Berghen: 50 (1954) [= M. umbel-

lata Steph.: 305 (1895b), nom. illegit.]. Type: Tanzania,

Usambara, Holst 692 (FH, G), syn. fide Bischl.: 83 (1993).

M. pappeana Lehm. subsp. pappeana, Bischl.: 82

(1993); Perold: 199 (1995c).

Thalli medium-sized to large, in densely

crowded mats; light green to yellowish green,

without dark median band, areolate, flecked

with whitish oil cells, air pores quite large, mar-

gins usually hyaline, occasionally purple, undu-

late, scalloped, mostly crisped, entire; when dry,

margins rarely raised, not incurved. Branches

rather distantly and irregularly furcate, not rib-

bon-like or flat, terminal segments oblong to

obovate, 10-15 mm long, (6.0-)7.0-8.5(-10.0)

mm wide, 740-925 pm thick medianly, in sec-

tion ± 9 times wider than thick, apex notched,

median scale appendages recurved over edge;

groove absent, thallus margins acute; flanks

sloping obliquely; ventral face medianly keeled.

Scales in 4 ventral rows, extending over 2/s — V4

of thallus width: median scales with body

obliquely triangular, purple, 800-1 125 pm long,

base arched, 1430-1875 pm wide, margins

sometimes with protruding papillae, narrowing

upwards and deeply constricted where joined

with appendage, scattered oil cells present,

appendage of median scales ovate to orbicular

or broadly triangular, purple-brown or reddish,

520-550 x 375-530 pm, apex mostly acute,

sometimes shortly apiculate, basally rounded or

cordate, margins entire or sometimes bluntly

toothed, marginal cells only slightly smaller

than large inner cells, oil cells solitary, rarely

more numerous; laminal scales lateral to medi-

an scales, mauve with hyaline base, obtusely tri-

angular, (750— )980— 1 125 pm long, base

(360-)630-1075 pm wide, longer than wide,

margins often with protruding papillae, oil cells

scattered throughout.

Dorsal epidermal cells mostly unistratose,

hyaline, 5- or 6-sided, 42.5-80.0(-105.0) x

22.5-37.5 pm, thin-walled; air pores raised,

compound, (65— )90— 1 05 x 70-100 pm, sur-

HEPATOPHYTA: March anti aceae

97

rounded by 6 or 7 concentric rings of cells, 3 or

4 above epidermis and 2 or 3 projecting into air

chambers, inner opening with 4 or 5(6) cells,

inside walls convex or almost straight.

Assimilation tissue 60-90 pm thick, air cham-

bers in single storey, crowded with chlorophyl-

lose filaments, bounding walls 2 or 3 cells high;

storage tissue occupying most of ventral part of

thallus medianly, decreasing laterally, sclerotic

cells present or absent, mucilage openings few

or absent; oil cells scattered throughout tissues.

Cupule margins with cilia up to 6(7) cells

long, exterior occasionally also ciliate.

Dioicous. Antheridiophore arising from apex

of terminal segment of main branch, raised on

stalk; receptacle 9-14 mm diam., palmate, dis-

sected into 6-8 rays, 1.7-3. 4 mm long, ± 3.5

mm wide, basal sinus 120-140°, ray margins

reddish, undulating, entire; median scales on

ventral side of rays brownish, obtusely triangu-

lar, body ± 750 x 500 pm, appendage tapering

to acute apex, 350-375 x 125-250 pm. Stalk

9— 1 8(— 32) mm long, 775-925 pm diam., with

2(3) rhizoid furrows, air chambers absent;

scales at base of stalk 1 or 2, hyaline, broadly

triangular, 1000-1150 x 550-750 pm, some-

times with appendage, ± 675 x 500 pm, partly

or not constricted at base; scales along length of

stalk narrowly triangular and tapering toward

apex, up to 1300 pm long, base ± 175 pm wide.

Arche goniophore arising from apex of terminal

segment of main branch, raised on stalk; car-

pocephalum (6.5— )8.0— 1 1.0 mm diam., with

small, rounded, median projection dorsally,

shortly and ± symmetrically divided into 9-11

lobes (occasionally 1 or 2 lobes replaced by

male rays), 1.4-1. 7 mm long, base narrow,

widening toward truncate apex, basal sinus ±

30°; scales of carpocephalum mauve or hyaline,

tapering toward apex, occasionally forked, up to

3250 x 250 pm, apices filamentous, ± 450 pm

long, papillate marginally, several oil cells pre-

sent. Stalk 1 6— 32( — 60) mm long, 850-1250 pm

diam., with 2 separate and opposite bands of air

chambers and 2 rhizoid furrows; scales at base

of stalk, 1 or 2, shape irregular, ± 1350 x 850

pm, often with triangular appendage, 750-900

Map 9. — Q Marchantia pappeana subsp. pappeana

A M. debilis

x 500-550 pm; scales along length of stalk

tapering, apically with filamentous, hyaline

strands. Involucre with margins hyaline, deli-

cately ciliate, cilia sometimes collapsed, 187.5-

200.0 pm long. Figure 22. Spores 22.5-30.0 pm

diam., triangular-globular, yellow-brown; distal

face with irregular, ± smooth ridges, forming

incomplete alveoli filled with nodules; proxi-

mal face with faint triradiate ridge, each facet

densely covered with nodules, some discrete,

others confluent, narrowly winged, margin

entire. Elaters yellow-brown, up to 825 pm

long, 7.5 pm wide, tapering toward ends, 5.0

pm wide, bispiral. Chromosome number: n = 18

(Bischler-Causse 1993). Plate 9E, F.

Marchantia pappeana is widely distributed

in tropical Africa, Bischler-Causse (1993)

reporting it from the Cape Verde Islands to

Ethiopia and south to southern Africa, general-

ly at an altitudinal range of 1 000-2 500 m. In

southern Africa it is known from North-West,

Northern Province, Gauteng, Mpumalanga, Swa-

ziland, Free State, KwaZulu-Natal and Lesotho.

It has also been collected at Kirstenbosch

Botanical Garden, Western Cape, a number of

times and the type specimen is from Promon-

torium Bonae Spei. Map 9.

Marchantia pappeana often grows in the

same localities as M. debilis, on vertical soil

98

HEPATOPHYTA: Marchantiaceae

S

HEPATOPHYTA: Marchantiaceae

99

banks of streams, at waterfalls, at sluice canals,

very rarely on rotting wood or on rocks, in open

grassland or in forests, sometimes in deep

shade.

Generally, the species can be distinguished

by being larger than M. debilis and by lacking a

dark median line on the dorsal surface of the

thallus; its median scale appendages are large

and often marginally toothed, with the inner

cells large, presenting a ‘loose’ appearance; its

cupules have longer cilia; the female receptacle

is shortly divided into rays and the involucral

margin is ciliate; androgynous branches in the

female receptacle are sometimes present.

M. pappeana subsp. pappeana differs from

M. pappeana subsp. robusta (Steph.) Bischl., a

close relative in South India and Sri Lanka, by

the latter having numerous sclerotic cells and

mucilage cavities in the thallus; oil bodies in the

median scale appendages are, however, absent.

Vouchers: Bottomley CHJ335; Burgoyne

2068; Hilliard & Burn 15460 (BOL); Per old &

Koekemoer 2841; Scheepers 562.

Subgenus Chlamidium section Papillatae Bischl. in Cryptogamie, Bryologie et Lichenologie 10:

69 (1989b); Bischl.: 99 (1993). Type: M. papillata Raddi [PI, lecto., Bischl.: 95 (1984)].

Thalli with branches rather narrow, (2. 1— )4.5— 7.3 mm wide, ribbon-like, often quite regularly

spaced, moderately to widely divergent; median scales with appendage orbicular or ovate, apical-

ly acute or apiculate, seldom obtuse, basally rounded, width across widest part 275-340 pm, mar-

gins toothed, oil cells absent.

Dorsal epidermis without papillae; air pores with inner opening bordered by cells, their inside

walls convex or straight.

Cupule margins with short cilia, 3(4) cells long and 1 or 2 cells wide basally, externally without

papillae.

Dioicous. Antheridiophore with receptacle smallish, palmate, asymmetric and deeply divided

into (4)5-7 rays, dorsal surface without papillae. Arche goniophore with carpocephalum smallish,

dorsally bearing a rounded median projection and deeply divided into 8-10 lobes, these basally

convex and costate, apically broadened. Stalks of gametangiophores basally surrounded by small-

er, narrowly triangular scales. Involucre margins entire or crenulate. Spores 25-32 pm diam.; dis-

tal face ornamented with irregular ridges, forming incomplete alveoli filled with granules; proxi-

mal face densely verruculose.

Only M. debilis of the southern African taxa belongs to this section. Bischler-Causse (1993)

states that it is closest to the Asiatic species, M. emarginata subsp. tosana. The ornamentation of

the spores is of the papillata type. The section differs from sect. Paleaceae and sect. Chlamidium

in the shape of the female receptacle, with the lobes costate basally and broadened apically.

Figure 22. — Marchantia pappeana subsp. pappeana. A-C, thallus: A, dorsal face; B, ventral face; C, cross section

D-F, air pore: D, from above; Ei, E2, from below; F, c/s with dorsal epidermal cells and part of air chamber. G, margin of

thallus; Hi, H2> laminal scales; I,, 12, median scales; Ji-Ji, appendages of median scales; K,. K2, margins of cupules; Lu L2,

female receptacles from above; M, female receptacle from side; N, male receptacle; O, c/s of female stalk; P, c/s of male

stalk; Q, median scale of male receptacle; R, scale from along male stalk; S, scale from foot of male stalk; T L— Ti, scales

from female receptacle; U, scale from foot of female stalk; V, scale from along female stalk; W, margin of male ray; X, mar-

gin of involucre. A, G, Hi, I2, J2, Ki, L,, L2, M, T|-T3, X, Koekemoer 1050 : B, C, F, Ji, K2, N, Perold & Koekemoer 2918:

D, O, V, Burgoyne 2068: Ei, S, H. Anderson 1261', E2, F, F. H2, Perold & Koekemoer 2841 ; P-R, W, Hilliard & Burn 15460:

U, H. Anderson CH13278. Scale bars: A, B, L-M, 2 mm; C, 1 mm; D-G, 50 pm; H-V, X, 250 pm; W, 100 pm Drawings

by M. Steyn.

100

HEPATOPHYTA: Marchantiaceae

5. Marchantia debilis K. I. Goebel in

Organographie der Pflanzen. 1. Bryophyten 2,

edn 2: 901 (1915); Bischl.: 100 (1993); Perold:

201 (1995c). Type: Cameroon, Urwaldgebiet

von Bipindi, Zenker, Flora von Kamerun exs.

1339 (BM!, BR, E, F, G!, GOET, M, S, iso.).

M. chevalieri Steph. in Bonner: 103 (1953). Type: Ivory

Coast, Haute Cote d’Ivoire, pays Dijola, environs de Ona,

4-1909, Chevalier s.n. (G, PC).

Thalli smallish to medium-sized, in crowded

patches, rarely in partial rosettes; green, occa-

sionally purplish all over, medianly with bro-

ken, dark, narrow, longitudinal band, areolate,

air pores quite small, margins narrowly reddish

purple or hyaline, entire, occasionally slightly

crisped; when dry, margins not raised or in-

curved. Branches repeatedly pseudodichoto-

mously furcate, sometimes quite regularly so,

ribbon-like, rather flat, apical segments oblong

or broadly lingulate, 5-12 mm long, 4. 5-7. 3

mm wide, 675-850 pm thick medianly, in sec-

tion 7 or 8 times wider than thick, apex notched,

with median scale appendages recurved over

edge; groove absent, thallus margins acute, thin;

flanks sloping obliquely; ventral face medianly

keeled, purplish. Scales in 4 ventral rows,

extending over 7/i« or more of thallus width:

median scales with body ± obliquely triangular,

brownish or purplish, upper margins serrate, up

to 625 pm long, base slightly arched, up to 3000

pm wide, narrowing upwards and constricted

where joined with appendage, scattered oil cells

present throughout, appendage of median scales

orbicular or ovate, reddish brown or mauve,

350-375 x 275-340 pm, apex acute or apicu-

late, rarely rounded, basally narrowed, margins

toothed, cells smaller than inner cells, oil cells

absent; laminal scales lateral to median scales,

brownish, ± ovate, 450-560 pm long, base

430-670(-900) pm wide, wider than long, mar-

gins sometimes ± papillate, oil cells rare or

absent.

Dorsal epidermal cells mostly unistratose,

generally hyaline, polygonal, (4)5-7-sided,

37.0-62.5 x 22.0-32.0 pm, thin-walled; air

pores raised, compound, 37.5-62.5 x 40.0-52.5

pm, surrounded by 4(5) or 6 concentric rings of

cells, 2 or 3 above epidermis and 2 or 3 project-

ing into air chambers, inner opening with 4 or 5

cells, inside walls ± convex or nearly straight.

Assimilation tissue up to 150 pm thick, air

chambers in single storey, crowded with chloro-

phyllose filaments, bounding walls 2 or 3 cells

high; storage tissue occupying most of ventral

part of thallus medianly, decreasing laterally,

sclerotic cells and mucilage cavities usually

absent; oil cells scattered throughout tissues.

Cupule margins with short cilia, 1-3 cells

long.

Dioicous. Antheridiophore arising from apex

of terminal segment of main branch or of short

lateral branch, raised on stalk; receptacle

7. 5-9.0 mm diam., asymmetric, dissected into

(4)5-7 rays, 1. 5-3.0 mm long, ± 1.2 mm wide

at base, narrowing slightly to tip, basal sinus ±

130°, ray margins hyaline, undulating, entire;

median scales on ventral side of rays, hyaline or

mauve, obtusely triangular, up to 1000 x 670

pm, margin with some papillae, sometimes with

apical appendage, which is basally constricted

or not, narrowly to broadly triangular, 300-430

x 100-200 pm, brownish with mauve cell

walls. Stalk (2. 5-)7. 0-16.0 mm long, 625-700

pm diam., with 2 rhizoid furrows, reduced air

chambers in single band; scales at base of stalk,

narrowly triangular, 750-1250 pm long,

150-500 pm wide at base, margins with few

papillae, sometimes ± midway divided into (2)3

tapering segments, apices filamentous; scales

along length of stalk filiform, up to 1100 x 50

pm, 2 or 3 cells wide, apical cells uniseriate.

Arche goniophore arising from apex of terminal

segment of main or short lateral branch, raised

on stalk; carpocephalum (3.5— )4.5— 7.0(— 9.0)

mm diam., with small rounded projection medi-

anly, deeply dissected into 8-10 lobes, 0.8-1.25

mm long, narrower at base, widening toward

apex, basal sinus 40-60°; scales of car-

pocephalum hyaline or yellow-brown or purple,

irregularly shaped, tapering toward apex,

800-1000 x 330-370 pm. Stalk 9-16 mm long,

400-550 pm diam., with 2 rhizoid furrows, and

generally a single band of air chambers, rarely 2

bands; scale(s) at base of stalk brownish, ± tri-

angular, 900-1000 x 400-450 pm, apex fili-

HEPATOPHYTA: MARCHANTIACEAE

101

form with 3 or 4 single cells in a row; scales

along length of stalk scattered, ± 700 x ] 12 pm,

tapering upwards, ± 35 pm wide. Involucre with

margins hyaline, entire or crenulate. Figure 23.

Spores 25.0-32.5 pm diam., faintly triangular-

globular, brown; distal face with irregular,

coarse ridges, forming incomplete alveoli,

spaces in between filled with granules; proxi-

mal face with triradiate mark hardly visible,

facets densely verruculose. Elaters brown, up to

295 pm long, ± 7.5 pm wide, bispiral. Chro-

mosome number: unknown. Plate 10A, B.

Marchantia debilis is widely distributed in

Africa and occurs from Morocco to southern

Africa, as well as on Reunion and in the eastern

part of Madagascar. In the FSA region it occurs in

the summer rainfall areas of Northern Province,

Gauteng, Mpumalanga, Swaziland, Free State,

KwaZulu-Natal, Lesotho and Eastern Cape. Map 9.

The species generally grows on damp soil on

vertical stream banks or waterfalls, on mud (or

occasionally on stones) of stream beds, at weirs,

or sluice canals, on stone dam walls kept wet by

spray, and on soil overlying sandstone or gran-

ite, in open grassland or in forests, sometimes in

partial shade.

Sterile plants of M. debilis can be distin-

guished from M. pappeana, the species it has

frequently been confused with, by the smaller

size of the rather ribbon-like thallus branches,

the dark median line on the dorsal face of the

thallus, the smaller appendages of the median

scales and by the shortly ciliate or almost entire

margins of the cupules. Fertile plants should not

be difficult to identify as the smallish male and

female receptacles, the latter with deeply divid-

ed lobes, are quite distinctive and the margin of

the involucre is entire.

Bischler-Causse (1993) states that this

species, which is confined to Africa, had not

been mentioned since its description by Goebel

(1915) and that it occurs in various herbaria

under 14 different names, but most commonly

under M. wilmsii, M. planiloba and M. cheva-

lieri. She was able to resolve the taxonomy of

this species. In Stephani’s herbarium, she found

that 13 of the 16 ‘M. wilmsii ’ specimens belong

to M. pappeana and only three to M. debilis.

She concluded that Stephani probably had M.

pappeana in mind, and not M. debilis, since he

clearly described M. pappeana under the epithet

M. wilmsii.

Vouchers: Bester 2544; Dieterlen 850; Glen

1690; Koekemoer 1049; Perold 3261 ; Van Rooy

1012.

Subfamily DUMORTIEROIDEAE

Dumortieroideae R.M.Schust. in Phytologia 56: 71 (1984a); R.M.Schust.: 375 (1992c). Type:

Dumortiera Nees ex Reinw.

Thalli large, in extensive mats or sheets; dark green, thin, translucent. Branches broadly and

rather irregularly strap-shaped, pseudodichotomously furcate, occasionally articulate, with apical

and/or ventrolateral innovations, apex notched; groove absent, thallus dorsally flat, margins thin,

undulate, to nearly flat, occasionally scalloped, sparsely hirsute; flanks sloping very obliquely;

ventral face medianly keeled. Scales vestigial, without appendages, evanescent.

Dorsal epidermis, air pores and assimilation tissue absent, dorsally ± smooth, but sometimes

with vestigial and ephemeral faint ridges delimiting polygonal areas of open air chambers, cells in

‘floor’ of air chambers small, chlorophyllose; storage tissue with large, hyaline cells often con-

taining starch grains; oil cells rare.

Asexual reproduction absent.

102

HEPATOPHYTA: Marchantiaceae

HEPATOPHYTA: MARCH ANTI ACEAE

103

Monoicous or ?dioicous. Antheridiophore subsessile, on very short stalk with 2 rhizoid furrows,

arising apically; receptacle disciform, antheridia dorsally sunken, margins fringed with hairs,

underneath with filiform scales. Gynoecial receptacle raised on stalk arising from apical notch of

thallus; carpocephalum disciform, radially grooved above by sinuses, mostly lacking air pores and

air chambers, but with scattered, bristle-like hairs, ventrally 6-8(-10)-lobed. Stalk ± 4 mm long,

with 2 rhizoid furrows, at apex with filiform, hyaline scales. Involucres fleshy, saccate, apices with

narrow, slit-like openings. Pseudoperianth absent. Sporophyte with foot, longish seta and ellipsoid

capsule, wall unistratose, with annular or semi-annular thickenings, dehiscing by 4 irregular valves.

Spores small; distal face rounded; proximal face ± flat, ornamented with numerous nodules. Elaters

tapering at ends, bispiral. Chromosome numbers : n = 9, 18, 27.

The subfamily Dumortieroideae is monotypic with the only genus Dumortiera placed here.

DUMORTIERA

Dumortiera Nees in Nova acta academiae caesareae Leopoldino-Carolinae germanicae naturae

curiosorum XII: 410 (1824); Gottsche et al.: 542 (1844-1847); Schiffn.: 35 (1893); Steph.: 222

(1899); Sim: 25 (1926); Mull.Frib.: 394 (1951-1958); S.W.Arnell: 52 (1963a); Hassel de

Menendez: 182 (1963); R.M.Schust.: 377 (1992c); Perold: 49 (1993a).

Synonymy according to Nelson & Parnell: 35 (1992).

Hygmpyla Taylor: 390 (1836).

Hygrophila Taylor (orth. var.) in J.Mackay: 53 (1836) non R.Br. (1810).

Hygrophyla Taylor (orth. var.) in J.Mackay: X (1836).

Hygropila Taylor (orth. var.) in Hook.f. & Taylor: 576 (1844).

Askepos Griff.: 340 (1849).

The generic diagnosis is contained in the diagnosis of the subfamily.

Dumortiera hirsuta (Sw.) Nees in Nova

acta Academiae Caesareae Leopoldino-Carolinae

Germanicae Naturae Curiosorum XII: 410 (1824);

Gottsche et al.: 542 (1844-1847); Spruce: 566

(1885); Steph.: 224 (1899); Macvicar: 41 (1926);

Sim: 25 (1926); Mull.Frib.: 396 (1951-1958);

S.W.Arnell: 52 (1963a); Hassel de Menendez:

182 (1963); R.M.Schust.: 383 (1992c); Perold:

49 (1993a). Type: Jamaica, leg. Swartz s.n. [S,

holo.!; MW, iso., Hb. Hoffm. No. 8497 ; UPS,

fide Grolle (1976)].

Marchantia hirsuta Sw.: 145 (1788).

M. irrigua Wilson in Hook. (1833) and in Sm.: 106 (1833).

Hygrapyla irrigua (Wilson in Hook.) Taylor: 390 (1836);

J.Mackay: 54 (1836); Steph.: 150 (1899). Dumortiera irri-

Figure 23. — Marchantia debilis. A-C, thallus: A, dorsal face with cupules; B, ventral face; C, cross section. D-F, air

pore: D, from above; Ei, E2, from below; F, c/s with dorsal epidermal cells and air chamber. G, margin of thallus; Hi, H2,

laminal scales; E, I2, median scales; Ji, J2, appendages of median scales; Ki, K2, margins of cupules; Li, L2, female recep-

tacles from above; M, female receptacle from side; N, male receptacle; O, c/s of male stalk; P, c/s of female stalk; Qi, Q2,

median scales of male ray; R, scale from along male stalk; S, scale from along female stalk; T, scale from base of female

stalk; U, scale from base of male stalk; V,-V3, scales from female receptacle; W, margin of male ray; X. margin of involu-

cre. A, H. Anderson CH1223; B, R, U, W, X, Mogg 6172; C-G, H2, J,, K,, Candy 90; H,, I,, I2, K2, Bester 2544; J2, Glen

1940; L,, L2, M, P, S, T, Dieterlen 850; N, Sim CH1345; O, Perold 2891; Q,, Q2, V,-V,, Perold 3048. Scale bars: A-B.

L-N, 2 mm; C, 1 mm; D-G, 50 pm; H-K2, 0-V3, 250 pm; W, X, 100 pm. Drawings by M. Steyn.

104

HEPATOPHYTA: Marchantiaceae

F

HEPATOPHYTA: Marchantiaceae

105

gua (Wilson in Hook.) Nees: 159 (1838). D. hirsute i Sw. var.

irrigua (Wilson in Hook.) Spruce: 566(1885). Type: Ireland,

Turk Cascade, near Killamey, Mr Wilson.

D. hirsuta Sw. var. angustior Gottsche et al.: 544 ( 1 844-

1847).

D. hirsuta Sw. var. intermedia Gottsche et al.: 544 ( 1 844 —

1847).

D. velutina Schiffn.: 156 (1898).

Askepos brevipes Griff.: 340 (1849). Type: India, in sylvis

umbrosis Tingrei agri, 11-1836.

Thalli very large, in extensive mats or sheets;

uniformly dark green, hygrophylous, thin, trans-

lucent, from above mostly smooth, rarely with

vestigial and ephemeral polygonal ridges, pores

absent, margins undulate, occasionally scalloped,

sparsely hirsute; when dry, crisped and shrivelled,

dull, margins not raised. Branches creeping, once

to several times pseudodichotomously furcate,

occasionally articulate with ventrolateral or api-

cal innovations, apical segments broadly and ir-

regularly strap-shaped, 50-95(-200) mm long,

8—1 3(— 22) mm wide, ± 500 pm thick medianly,

in section 16-26 times wider than thick, apex

notched, without scale tips; groove absent, thal-

lus dorsally flat, margins acute, thin, sparsely hir-

sute; flanks sloping very obliquely; ventral face

medianly keeled. Scales in 2 ventral rows, only

toward apex, hyaline, vestigial, without append-

ages, evanescent, marginally with slime papillae.

Dorsal epidermis , air pores and assimilation

tissue absent; surface cells of thallus unistratose,

thin-walled, chlorophyllose; margins with sparse

hairs, ± 250 pm long, tapering slightly to some-

what blunt tip; storage tissue with ± 18 cell rows

medianly, cells larger, angular in upper 3 rows,

walls wavy, with scattered chloroplasts, lower

down cells smaller, lacking chloroplasts, cell

rows decreasing in number laterally; oil cells

quite rare, mostly confined to keel.

Asexual reproduction absent.

Monoicous or ?dioicous. Androecial recept-

acle subsessile, disciform, ± 2.8 mm diam.,

antheridia sunken, bristle-like hairs, 600-1100

pm long, dorsally scattered, densely fringing

margins, underneath with filiform, hyaline

paleae. Stalk arising from apical notch of thallus,

very short, with 2 rhizoid furrows, air chambers

absent. Gynoecial receptacle arising at apical

notch of thallus between overlapping sides; car-

pocephalum disciform, ± 3.8 mm diam., central-

ly convex above, mostly lacking air pores and

chambers, radially grooved by sinuses, ventrally

with 6 — 8(— 1 0) lobes in radiating rows, almost

star-shaped, sparsely bristled. Stalk ± 4 mm

long, 925 pm wide, with 2 rhizoid furrows, air

chambers absent, summit encircled by numer-

ous, filiform or lanceolate, hyaline paleae, up to

3750 pm long, 300 pm wide at base, oil cells

absent. Involucres green when young, fleshy,

saccate, apices with narrow, slit-like openings,

through which long archegonial necks protrude,

at maturity generally only one sporophyte in

each involucre, rarely 2, sometimes none.

Pseudoperianth absent. Sporophyte with longish

seta, capsule ellipsoid, wall unistratose, with

annular or semi-annular thickenings, dehiscing

irregularly by 4 valves. Figure 24. Spores 25-30

pm diam., ± hemispherical, golden brown, semi-

transparent, ornamented with numerous nodules

or tubercles, irregular in size and shape; distal

face rounded; proximal face ± flat to slightly

peaked in centre, triradiate mark indistinct.

Elaters yellow-brown or orange-brown, 225^470

pm long, 7.5-10.0 pm wide in centre and 3.5

pm wide at tapered ends, bispiral. Chromosome

number n = 9. Plate 10C, D.

Dumortiera hirsuta is subcosmopolitan and is

widespread and common in tropical and temper-

ate regions, but rare in the British Isles and

Europe and seemingly absent from southern

Figure 24. — Dumortiera hirsuta. A-C, F-H, thallus: A, dorsal face; B, ventral face; C, male with disciform recepta-

cles at apices; F, cross section; G, margin with hairs; H, c/s, much enlarged. D, E, young female receptacle: D, from above;

E, from below. I, c/s of lower cells of costa and vestigial scales; J, filiform palea from top of stalk; K, c/s of stalk with two

rhizoid furrows. L, M, capsule wall: L, cells with thickenings; M, cross section. A, F-H, Perold 2694, B, Perold 2634\ C,

Nicholas 1176\ D, E, I, H. Anderson CH 13495', J-L, Doidge CH3581. Scale bars: A-C, 2 mm; D-F, J, 1 mm; G, K, 100

pm; H, I, L, M, 50 pm. Drawings by G. Condy.

106

HEPATOPHYTA: March ANTI ACEAE

Plate 10. — Spores and elater. A, B, Marchantia debilis: A, distal face; B, proximal face. C, D, Dumortiera

hirsuta: C, distal face; D, elater. E, F, Oxymitra cristata: E, distal face; F, proximal face. A, B, Preuss s.n.\ C, D,

H Anderson CH4527 ; E, F, Volk 00906. A, x 1810; B, x 1760; C, x 2280; D, x 310; E, F, x 420.

HEPATOPHYTA: Marchantiaceae/Ricciineae

107

South America and Australasia. In southern

Africa it is known from the North-West, Northern

Province, Mpumalanga, Swaziland, KwaZulu-

Natal, Western and Eastern Cape. Map 10. It gen-

erally grows in sheltered, wooded, shaded and

damp areas, on soil or on rock.

Specimens of D. hirsuta are easily recog-

nized even when sterile, by the large, thin and

translucent, dark green thalli lacking a dorsal

epidermis, air pores and air chambers, as well as

by the sparsely hirsute margins.

All southern African specimens have been

identified as belonging to D. hirsuta ; D. nepal-

ensis (with 18 chromosomes) is absent from

Europe and Africa; a Japanese species, D.

Hiroshima , is said to have 27 chromosomes

(Schuster 1992c).

Map 10. — • Dumortiera hirsuta

□ Oxymitra crtstata

Vouchers: Bosnian 3318; Gerstner 4386; Glen

2881; Koekemoer972; Perold & Koekemoer2864;

Stirton 9648.

SUBORDER RICCIINEAE

Ricciineae H.Buch , Suomen Maksasammalet: 39, 107 (1936); R.M.Schust.: 622 (1953); R.M.Schust.:

394 (1992c); Mull.Frib.: 409 (1951-1958); S.W.Arnell: 276 (1956a); S.W.Arnell: 10 (1963a).

Thalli small to large, in gregarious patches or scattered or in partial to complete rosettes; light

green to yellow green to deep green; terricolous, rarely aquatic. Branches once to several times

pseudodichotomously furcate, oblong or ovate or obovate, occasionally linear, apex truncate to

rounded, emarginate; groove median along dorsal face, sometimes only present toward apex, thal-

lus margins acute to obtuse, glabrous, occasionally ciliated; flanks sloping obliquely or steep; ven-

tral face rounded to flat. Scales lacking distinct appendages, often large, lateral, imbricate, hyaline

or variously coloured, purple, red or black, sometimes ventral and in a single (or split) median,

transversely inserted, well-spaced row, rarely absent.

Dorsal epidermis chlorophyllose or hyaline, cells in 1 or 2 storeys or in free uniseriate multi-

cellular pillars; air pores simple, spaced, surrounded by one ring of 4-6 differentiated cells, with radi-

al walls thickened in Oxymitra, or surrounding cells undifferentiated or pores not defined, numer-

ous, small regular openings in Ricciaceae. Assimilation tissue either spongy, with unistratose cell

walls enclosing wide, empty, polyhedral air chambers in one to several storeys, or compact, with

cell columns enclosing narrow, vertical air canals; storage tissue occupying ventral part of thallus,

compact; oil cells only present in Ricciocarpus ; rhizoids dimorphic, numerous in terrestrial plants,

absent in aquatic forms.

Asexual reproduction sometimes by tubers or bulbils or perennation, rarely by ventral stolons.

108

HEPATOPHYTA: Ricciineae/Oxymitraceae

Monoicous or dioicous. Gametangia on or below dorsal surface of thallus and then embedded,

with only necks projecting, in defined groups in Oxymitra, otherwise median along groove or scat-

tered. Sporophytes in groups enclosed above by continuous crest-like involucre in Oxymitra or in

Ricciaceae surrounded by unspecialized thallus tissue, foot and seta lacking, calyptra wall uni-

stratose, capsule globose, its wall also mostly unistratose, without thickening bands, resorbed during

spore maturation, cleistocarpous, spores freed by rupture of dorsal or ventral thallus tissue. Spores

generally large, separating at maturity, rarely remaining in tetrads, triangular-globular or subglobular,

ornamentation mostly reticulate. Elaters absent. Chromosome number : n = 9, 18 in Oxymitraceae;

8, sometimes multiples of 8 (or other) in Ricciaceae.

Two families are placed in the suborder Ricciineae: Oxymitraceae and Ricciaceae.

Key to families of Ricciineae

Assimilation tissue with tall air chambers, in one storey, subvertical, rather narrow, 4-7-

sided; air pores simple, stellate, with thickened radial walls; gametangia on dorsal sur-

face of thallus in defined groups; sporangia in groups enclosed above by a continuous,

crest-like involucre (or in extra-southern African species individually enclosed in sepa-

rate, pyriform involucres) Oxymitraceae

Assimilation tissue with wide air chambers, in one or more storeys, or with narrow, vertical,

canal-like air spaces; air pores simple, surrounded by undifferentiated cells, or mere

exits of air canals; gametangia sunken within thallus; sporangia ripening internally,

lacking an involucre Ricciaceae

Schier (1974), on the basis of biochemical studies, segregated the Oxymitraceae from the

Ricciineae in a distinct suborder, the Oxymitrineae, but this has not been followed here.

OXYMITRACEAE

Oxymitraceae Miill.Frib. in Dr L. Rabenhorst’s Kryptogamen-Flora 6,2: 286 (1940b); Miill.Frib.:

410 (1951-1958); Grolle: 215 (1972); R.M.Schust.: 399 (1992c).

Thalli medium-sized, in gregarious or rosette-like patches; pale green to deep green. Branches

simple or once/twice furcate, broadly ovate or oblong, apex emarginate; groove medianly sharp and

deep, thallus margins acute; flanks sloping obliquely; ventral face rounded to flat. Scales lateral,

projecting far above thallus margins, obliquely triangular, dark red to almost black in local species.

Dorsal epidermis hyaline, persistent; air pores tiny, simple, stellate, radial walls of surrounding

cells thickened. Assimilation tissue with one storey of empty, tall, narrow, subvertical or polygonal

air chambers, bounded by unistratose walls of chlorophyllose cells; storage tissue compact, occu-

pying ventral part of thallus.

Asexual reproduction reputed to be by tuber formation.

Monoicous or dioicous. Antheridia in median groups, proximal to archegonia, immersed in thal-

lus. Archegonia in median groups enclosed in flask-shaped cavities, partly sunken into thallus.

Involucre covering archegonia fleshy, continuous, crest-like (in local species). Sporophyte without

HEPATOPHYTA: OXYMITRACEAE

109

stalk or foot, capsule globose, wall hyaline, unistratose or locally bistratose, lacking thickening

bands. Spores triangular-globular; distal face with several large alveoli, each containing a central

nodule; proximal face with or without distinct triradiate mark, irregularly reticulate. Elaters absent.

Chromosome number, n = 1 8 or 9.

The family contains a single genus, Oxymitra, with only two species, the type species, O.

incrassata (Brot.) Sergio & Sim-Sim (better known as O. paleacea Bisch. ex Lindenb.) from the

northern hemisphere as well as South America, and the southern African O. cristata. O. incrassa-

ta differs from O. cristata, by individual, not fused involucres, by hyaline, not purple scales, by the

absence of a central nodule in the alveoli on the distal spore face, and by the smooth, not irregu-

larly reticulate proximal face.

OXYMITRA

Oxymitra Bisch. ex Lindenb. in Nova acta Academiae Caesareae Leopoldino-Carolinae Germa-

nicae Naturae Curiosorum, Suppl. 14: 124 (1829); Gottsche et al.: 597 (1844—1847); Frye &

L. Clark: 40 (1937); Miill.Frib.: 410 (1951-1958); S.W.Arnell: 11 (1963a); Hassel de Menendez:

200 (1963); Perold: 210 (1993b). Fectotype: O. incrassata (Brot.) Sergio & Sim-Sim (1989).

Pycnoscenus Lindb.: 606 (1863), noin. illegit.

Tessellina auct. non Dumort.: 78 (1822).

With characters of the family.

Oxymitra cristata Garside ex Perold in

Bothalia 23: 211 (1993b). Type: Cape, near

Bredby Mine (25 miles S of Kuruman), Schelpe

5900 ( BOL, holo.!).

Oxymitra cristata Garside: 83, 174a (1958). Types:

Schelpe 5900; Duthie 5531 (BOL), holo. not designated,

hence invalidly published.

Thalli smallish to medium-sized, in crowded,

overlying patches; bright green to deep green,

areolate, air pores tiny, margins dark red, scal-

loped or undulating; when dry, thallus margins

incurved or raised and clasped together.

Branches simple or once/twice pseudodichoto-

mously furcate, narrowly to moderately diver-

gent, broadly ovate or oblong, (3— )5— 10(— 12)

mm long, 2.5 — 4.8 mm wide, 1100-2000 pm

thick medianly, in section ± twice wider than

thick, apex emarginate; groove deep along entire

midline, except where interrupted by gametan-

gia, thallus margins rather obtuse to acute; flanks

steep to sloping obliquely, deep purple; ventral

face rounded to flattish, green. Scales lateral,

covering flanks, obliquely triangular, dark red, to

almost black, shiny, in apical scales basal part

hyaline, closely imbricate, 1250-1375 pm long,

margins entire, sometimes crenate or shortly

toothed toward base of distal side, 1075-1200

pm wide across base, apex projecting up to 375

pm above thallus margins, oil cells absent.

Dorsal epidermal cells unistratose, hyaline,

polygonal, (22.5-)37.5-45.0(-52.0) x 27.5-37.5

(-47.5) pm; air pores slightly raised, small, sim-

ple, 5-10 pm wide, 4- or 5(6)-sided, stellate,

surrounded by one ring of 4 or 5, rarely 6, small,

bluntly wedge-shaped cells, radial walls slightly

thickened, partly overlying, or occasionally ad-

joining larger polygonal cells. Assimilation tis-

sue 400-600 pm thick, air chambers empty, in

one storey, bounding walls chlorophyllose, uni-

stratose; storage tissue occupying ventral part of

thallus, composed of rounded or angular cells, ±

50 pm wide; oil cells absent.

HEPATOPHYTA: Oxymitraceae/Ricciaceae

in

Monoicous. Antheridia in row along mid-

line, proximal to archegonia, immersed, necks

hyaline, cylindrical, protruding above dorsal

surface of thallus. Archegonia in median row, in

flask-shaped cavities, partly sunken into thallus.

Involucre ridged, enclosing archegonial groups,

± 600 pm high, irregular, fleshy, crest-like, tinged

reddish on top around openings of archegonial

necks, these long and turning purple with age.

Figure 25. Sporophytes ventrally partly sunken

into thallus, dorsally bulging on either side of

central crest, capsule globose, wall thin, delicate,

lacking thickening bands. Spores ( 1 08—) 1 1 0—1 15

(-125) pm diam., triangular-globular, black,

opaque, anisopolar, with ornamentation differ-

ent on two faces; distal face with 6 or 7 large,

central alveoli, up to 30 pm wide, smaller

toward margin, generally with a nodule and thin

radiating ridges in middle of each, alveolar

walls thick; proximal face with triradiate mark

distinct, 3 facets with incomplete alveoli, walls

irregular, sometimes rather indistinct, wing ± 5

pm wide, entire. Chromosome number, n = 18

(Baudoin 1976). Plate 10E, F.

Oxymitra cristata is endemic to southern

Africa, and very rarely collected. It is known

from Namibia, Free State, Northern and Eastern

Cape. Map 10. It has been found mainly on sub-

strates derived from ironstone, and it occasion-

ally grows in association with Plagiochasma

spp. and Riccia spp.

Oxymitra cristata is distinguished by its large,

obliquely triangular, shiny, dark red scales and by

the row of archegonia enclosed in an irregular,

but continuous, crest-like, fleshy ridge of tissue.

Vouchers: Burrows 2523; Cooke s.n.; Koeke-

moer 1024; Volk 5050 (herb. Volk); Zietsman

943.

RICCIACEAE

Ricciaceae Rchb., Botanik fur Damen, Ktinstler und Freunde: 255 (1828); Jovet-Ast: 291 (1986);

Perold: 17 (1991c).

Thalli small to large, scattered or in gregarious patches or in rosettes; green; terricolous, rarely

aquatic. Branches 2 or 3 times pseudodichotomously furcate, linear to obovate, apex truncate to

rounded, emarginate; groove often present, median along dorsal face, thallus margins acute to

obtuse, glabrous or occasionally ciliate; flanks sloping obliquely or steep; ventral face rounded to

flat. Scales lateral or ventral, small to large, rarely absent, generally imbricate, hyaline or variously

coloured, purple, red or black.

Dorsal covering either an epidermis, chlorophyllose, generally unistratose with air pores simple,

scattered and delimited, often enlarging and becoming lacunose; otherwise dorsal covering an

epithelium, hyaline, echlorophyllose, cells uni- or bistratose, or in free uniseriate, multicellular pillars

with air pores not defined, numerous, small, regular spaces. Assimilation tissue spongy, with mostly

unistratose cell walls bounding wide polyhedral air chambers, or else compact, with cell columns

enclosing narrow vertical air canals; storage tissue occupying ventral V2 or less of thallus. Rhizoids

long, unicellular, dimorphic, smooth or pegged, arising from ventral epidermis.

Asexual reproduction rare, sometimes by bulbils, perennation occasionally by ventral stolons.

Figure 25. — Oxymitra cristata. A-E, thallus: A, dorsal face with crest-like involucre and proximally, row of antheri-

dia; B, ventral face; C, c/s showing median dorsal groove; D, c/s through involucre with archegomum; E, c/s through

antheridium. F, c/s of dorsal cells and air chambers. G, H, air pore(s): G, c/s with dorsal epidermal cells; H, from above. I,

ventral scale. A, B, D, Volk 00906\ C, F-I, Volk 81/050', E, Volk 00957. Scale bars: A-E, 2 mm; F-H, 50 pm; I, 500 pm.

Drawings by A. Pienaar.

112

HEPATOPHYTA: Ricciaceae

Monoicous or dioicous. Gametangia acropetally arranged, embedded, only necks projecting,

median along groove or scattered. Sporophyte without stalk or foot, capsule globose, the uni-

stratose wall resorbed during spore maturation, surrounding venter wall soon disintegrating to

liberate spores. Spores generally large, separating at maturity, rarely remaining adherent in tetrads,

triangular-globular or subglobular, ornamentation mostly reticulate, often specific. Elaters absent.

Chromosome number : n = 8 usually, sometimes multiples of 8, or rarely 9, 10, 12, 15, 17 or 20.

The family comprises two genera: the monotypic, cosmopolitan genus Ricciocarpos, and the

species-rich genus Riccia, with up to ± 200 species worldwide, and particularly well represented in

southern Africa.

Key to genera of Ricciaceae

Thalli floating or temporarily terricolous; assimilation tissue with large air chambers in sev-

eral storeys; scales long, pendant, purple ribbons, but small in land form, margins dentate;

oil cells present; gametangia only along deep central groove Ricciocarpos

Thalli with very rare exceptions terricolous; assimilation tissue spongy, with air chambers, or

else compact, with cell columns enclosing narrow vertical air canals; scales small to large,

imbricate, mostly rounded, margins smooth, rarely denticulate; oil cells absent; game-

tangia along groove or scattered Riccia

RICCIOCARPOS

Ricciocarpos Corda in Opiz, Beitrage zur Naturgeschichte 12: 651 (1829) [orth. var.: Riccio-

carpon Corda (1829); Ricciocarpus Corda mut. Dumort. (1874)]; M.Howe: 26 (1899); Mull.Frib. :

44 (1951-1958); Hassel de Menendez: 205 (1963); S.W.Arnell: 12 (1963a); Perold: 72 (1991c);

R.M.Schust.: 415 (1992c). Type: R. natans (L.) Corda.

Hemiseuma Bisch.: 1040, 1071 (1835).

Hemiseumata Bisch. ex Lindl.: 57 (1847).

Thalli large, gregarious or in partial rosettes; olive-green to yellowish green; aquatic or tem-

porarily terricolous. Branches 2-3 times symmetrically furcate, hardly divergent, up to 14 mm

long, 3-7 mm wide, less than 1 mm thick, in section 4-8 times wider than thick, apex rounded,

emarginate; groove very pronounced throughout, dividing near apex, its sides obscuring central

ridge. Scales ventral, conspicuous, in dense, purple ribbons, margins dentate, pendant in water

form, small in land form.

Dorsal epidermis covering air chambers persistent, interrupted by simple air pores. Assimilation

tissue with several storeys of large, superimposed, polyhedral air chambers; storage tissue reduced

to only 3 or 4 layers of cells; oil cells present. Rhizoids mostly absent in aquatic form, smooth and

tuberculate in land form.

Monoicous. Sporangia rare, immersed in ridge along groove toward base. Spores smallish, tri-

angular-globular, polar, black, opaque, granulate-alveolate, ornamentation poorly defined.

Ricciocarpos is a monotypic genus and worldwide in its distribution. In southern Africa it is

infrequently collected in stagnant pans or still pools in forested regions, and in swamps or vleis.

HEPATOPHYTA: RlCCIACEAE

113

Ricciocarpos natans (L.) Corda in Opiz,

Beitrage zur Naturgeschichte 12: 651 (1829);

Steph.: 51 (1898); M. Howe: 33 (1899);

Schiffn.: 15 (1893); C.Massal.: 831 (1912);

Casares-Gil: 235 (1919); Macvicar: 30 (1926);

Frye & L.Clark: 39 (1937); Mull.Frib.: 414

(1951-1958); Hassel de Menendez: 205 (1963);

S.W.Amell: 12 (1963a); Vanden Berghen: 183

(1972); E.O.Campb.: 121 (1975); Perold: 72

(1991c); R.M.Schust.: 415 (1992c). Type:

Britain, Suffolk, ‘in stagnis, circa Hadley’, leg.

Buddie [OXF, holo. fide Grolle 87: 229 (1976);

H-SOL, iso. fide Isov. 89: 23 (1970) xerox

copy! Lichen no. 18, tab. 78, fig. 18, Dill.: 536

(1741)].

Riccia natans L.: 1339 (1753); Lindenb.: 121 (1829);

Nees: 319, 419 (1838); Gottsche et al.: 607 (1844-1847);

Sim: 15 (1926).

R. capillata Schmidel: 276 (1793).

R. velutina Wilson: t. 249 (1839).

Ricciocarpus velutinus Steph.: 758 (1898); Ladyz.: 3

(1943).

Thalli large, gregarious, occasionally in dense

mats or in partial rosettes, 20-30 mm across;

olive-green to yellowish green, margins tinged

with purple, firm and somewhat leathery, convex

above and areolate; when dry, deflated, otherwise

little altered, sides not inflexed. Branches 2-3

times pseudodichotomously furcate, shortly to

deeply divided, hardly divergent, broadly obcor-

date, narrow at base, 8-14 x 3-7 mm, less than 1

mm thick medianly, rapidly thinning toward mar-

gins, in section 4-8 times wider than thick, apex

rounded, emarginate; groove very pronounced

throughout, dividing near apex, containing cen-

trally raised ridge, obscured by highly convex

sides of groove that almost meet above it, thallus

margins thin and very acute in aquatic form,

fleshy and rather obtuse in land form; flanks slop-

ing very obliquely to almost flat; ventral face flat,

violet to brown. Scales ventral, small in land

form, in aquatic form up to 10 mm long, 375-600

pm wide, in several rows, in dense bunches of

Figure 26. — Ricciocarpos natans. A, dorsal face of thallus of aquatic form. B, C, dorsal epidermis with air pores

(hatched); C, with oil cells (solid specks), overlying air chambers left, thin marginal area right. D, E, scale: E, enlarged tip, oil

cells (solid specks) and toothed margin. F, c/s thallus. A-F, Ward s.n. Scale bars: A, F, 1 mm; B, E, 50 pm; C, D, 100 pm.

114

HEPATOPHYTA: Ricciaceae

Plate 1 1. — Spores. A, B, Ricciocarpos natans: A, distal face; B, proximal face. C, D, Riccia crystallina:

C, distal face; D, proximal face. E, F, R. cavernosa: E, distal face; F, proximal face. A, B, Ward s.n.; C, Duthie

& Garside 5529 (BOL); D, Arnell 150 (BOL); E, F. van der Merwe CH3595, F, Koch 14934. A, B, x 800; C, D,

x 1000; E, F, x 700.

HEPATOPHYTA: Ricciaceae

115

pendant ribbons, violet to reddish black, linear-

lanceolate to tapering, margins toothed, with

dark, projecting conical cells, oil cells occasional,

small, scattered.

Dorsal epidermis covering air chambers per-

sistent, cells hexagonal to polygonal, 25-50 x

15-27 pm; air pores 5- or 6-sided, ± 17.5 pm

wide, 5-8 surrounding cells slightly thicker-

walled. Assimilation tissue occupying most of

thickness of thallus, air chambers in several

storeys, superimposed, polyhedral, bounded by

unistratose cell walls; storage tissue only 3 or 4

layers of cells ventrally; occasionally with scat-

tered oil cells. Figure 26.

Monoicous. Antheridia along ridge in central

groove, hyaline necks ± 100 pm long. Arche-

gonia also along groove, but not together with

antheridia. Sporangia infrequent, single or up to

3 in sequence, immersed, the position marked

by a slight elevation. Spores (55-)60-67(-75)

pm diam., triangular-globular, polar, black,

opaque; wing narrow, margin crenulate; orna-

mentation granulate-alveolate; distal face with

6-8 poorly defined alveoli across diam. of

spore, entire surface thickly covered with gran-

ules; proximal face without defined triradiate

mark, alveoli absent, sprinkled with granules

and papillae. Chromosome number, n = 9 (Siler

1934; Mull.Frib. 1951-1958; Jovet-Ast 1974;

Bomefeld 1987). Plate 11 A, B.

Ricciocarpos natans is cosmopolitan and

although rare, is found in all parts of the world,

Map 11. — A Ricciocarpos natans

• Riccia crystallina

even in Alaska. In the FSA area Ricciocarpos

natans is known from Namibia, (East Caprivi),

Botswana, KwaZulu-Natal, including Zululand

and Eastern Cape. It floats on still water, often

in association with Lemna and Azolla, or

becomes stranded on mud at the margins of

pools or vleis. Map 1 1 .

It is distinguished by its somewhat leathery

appearance, conspicuous, pendant, marginally

serrate scales, and by occasional oil cells.

Vouchers: Pienaar & Vahrmeyer 474 (PRE);

Smith 1441 (PRE); Tinley 418 (PRE); Wager 55

(PRE).

RICCIA

Riccia L., Species plantarum: 1138 (1753); Steph.: 314 (1898); Sim: 8 (1926); Mull.Frib. : 416

(1951-1958); S.W.Arnell: 13 (1963a); Hassel de Menendez: 208 (1963); Na-Thalang: 71 (1980);

Jovet-Ast: 291 (1986); Jovet-Ast: 214 (1991); Perold: 19 (1991c); R.M.Schust.: 421 (1992b). Lecto-

type: R. glauca L., fide Hassel de Menendez: 208 (1963).

Euriccia Lindb. ex Lacout.: 23 (1905).

Ricciella A. Braun: 756 (1821).

Lichenoides (Bisch.) Lindl : 57 (1847).

116

HEPATOPHYTA: Ricciaceae

Cryptocarpus Austin: 231 (1870) nom. illegit.

Thallocarpus Lindb.: 377 (1874).

Atigiocarpus Trevis.: 444 (1877).

Riccinia Trab. in Douin & Trab.: 326 (1916).

Fysonia Kashyap in Kashyap & Sethi: 203 (1923).

Pteroriccia R.M.Schust.: 72 (1984a).

Thalli small to large, in gregarious patches or frequently in rosettes; terricolous, very rarely

aquatic. Branches once to several times symmetrically or asymmetrically furcate; groove median,

deep or shallow, along length of branches or only apical. Scales lateral or ventral, vestigial to con-

spicuous, usually imbricate, rounded, very rarely triangular, hyaline or variously coloured.

Dorsal epidermis chlorophyllose, unistratose (rarely not so); air pores simple, scattered, stomata

delimited, becoming lacunose, or else if present, dorsal epithelium hyaline, echlorophyllose, cells

uni- or bistratose or in free, uniseriate, multicellular pillars; air pores small, regular spaces.

Assimilation tissue generally '/2 (or more) the thickness of thallus, spongy, with wide polyhedral

air chambers; otherwise compact, in vertical cell columns, enclosing narrow air canals; storage tis-

sue occupying ventral V2 or less of thallus, cells rounded, often containing starch granules; oil cells

absent. Rhizoids arising from ventral epidermis and sometimes from base of scales, some smooth,

others tuberculate, 15-25 pm wide.

Monoicous or dioicous. Antheridia sunken along groove, with protruding hyaline necks.

Archegonia also sunken, with protruding purple necks. Sporangia bulging dorsally or not, rarely

bulging conspicuously ventrally, usually containing several hundred spores, released by decay of

surrounding tissue. Spores in tetrads separating at maturity, rarely remaining adherent in tetrads,

mostly 80-110 pm diam., triangular-globular or subglobose; ornamentation on distal face general-

ly reticulate, alveoli small to large, otherwise papillate, verruculose or vermiculate; proximal face

divided into 3 facets by distinct or faint triradiate mark. Chromosome number: n = 8 usually, some-

times multiples of 8 or rarely 9, 10, 12, 15, 17 or 20.

The genus Riccia comprises up to ± 200 currently recognized species and has a worldwide dis-

tribution. It is primarily distributed in the temperate zones and tropics, but is also known from cold

climates. The greatest concentration of species is undoubtedly in southern Africa with more than

50 now known. Namaqualand in the northwestern Northern Cape has yielded several new, unusu-

al species. Riccia species frequently grow on soil at the margin of flat rock outcrops, at stream-

banks or at seepages.

Key to the subgenera, sections, groups and species of Riccia

la (lb: p. 118) Thalli covered by epidermis of mostly thin-walled, generally chlorophyllose

cells, very rarely bearing vertical, cellular outgrowths dorsally; air pores mostly delimit-

ed, often ringed by smaller cells, well spaced, fewer in number than in subgenus Riccia,

frequently enlarging and becoming lacunose; assimilation tissue loosely arranged,

spongy, unistratose cell walls enclosing large polyhedral air chambers; scales small and

evanescent to occasionally large and persistent; spore tetrads separating at maturity or

very rarely remaining in tetrads; habitat mostly mesic, rarely xeric or aquatic:

2a (2b: p. 118) Dorsal epidermis a single layer of thin- walled, closely joined, flattened cells

(rarely globose, and then somewhat loosely connected), interrupted by air pores,

becoming lacunose over air chambers or not; scales ventral, mostly hyaline and

inconspicuous, evanescent:

HEPATOPHYTA: RlCCIACEAE

117

3a Spores remaining in tetrads . . . B. subgenus Thallocarpus:

4a Thalli in complete or incomplete rosettes, 10 mm or more across; heterothallic;

spores joined together by narrow band or ridge into tetrahedral tetrads; ornamen-

tation with slender spinules up to 5 pm long (Plate 15E, F) 11./?. curtisii

4b Thalli reportedly in rosettes up to 11 mm across; heterothallic; spores joined together

by wide band into rhomboidal tetrads; ornamentation with stout spines 10-15 pm

long (Plate 16A, B) 12./?. perssonii

3b Spore tetrads separating at maturity ... A. subgenus Ricciella:

5a Thalli generally annual; not in rosettes; branches linear, strap-shaped or ‘ribbon-

like’, up to 15-20 x 0.5-2.0 mm; not lacunose dorsally; sporangia bulging markedly

ventrally . . . A2. section Ricciella:

6a Thalli monoicous; sometimes aquatic; sporangia obliquely borne (Figure 34D); dis-

tal spore face with alveolar walls thick and prominent; at times forming apical

stolons; widespread in mostly summer rainfall areas 9. R. stricta

6b Thalli dioicous; thin and lax; strictly terrestrial; sporangia vertically borne; distal

spore face with alveolar walls thin; at times forming apical stolons; distribution

restricted to winter rainfall areas of the southwestern Northern Cape and the

southwestern and southeastern parts of Western Cape 10. R. purpurascens

5b Thalli annual or perennial; sometimes in rosettes; branches not strap-shaped, 2-15 x

( 1 — )3 — 6(— 8) mm; dorsally lacunose to markedly lacunose; monoicous or dioicous;

sporangia deeply imbedded or bulging somewhat above or below . . . Al. section

Spongodes:

7a Thalli finely to coarsely spongiose; dorsally not deeply grooved; often in rosettes;

glaucous-green to yellow-green, sometimes tinged with red . . . A 1.1. group Crystal-

lina:

8a Thalli dioicous; markedly heterothallic with small male gametophytes (Figure

29); bright green to yellowish green; from above, air chamber walls visible or

dorsal epidermis lacunose; spores foveolate, triradiate mark pronounced (Plate

12D) 4. R. cupulifera

8b Thalli monoicous; from above, air chamber walls visible or not; spores complete-

ly or incompletely reticulate:

9a Thalli green to yellow-green, faintly red at margins; from above, walls of large air

chambers visible or dorsally lacunose (cavernose); spores 85-115 pm diam.;

red-brown to black, distal face centrally with thicker, irregularly bi- or tri-

chotomously branching ridges (Plate 11E) 2. R. cavernosa

9b Thalli blue-green, dorsally crystalline, with rounded cells, in tiers or not; scales

present or absent; spores 65-85 pm diam.; light brown; ornamentation on

proximal and distal faces similar or dissimilar:

10a Thalli dorsally crystalline and glistening, with rounded cells in loose, double

tiers; scales absent or evanescent; ornamentation on 2 spore faces similar,

alveoli regular and complete, walls thin, triradiate mark on proximal face

distinct (Plate 1 1C, D) 1. R. crystallina

10b Thalli dorsally finely areolate; scales present, purple or hyaline; spores with

2 faces dissimilar, proximal face with numerous small, shallow alveoli and

triradiate mark absent, distal face with 8-10 alveoli across width (Plate 12A,

B) 3. R. moenkemeyeri

7b Thalli swollen to rather flat; usually markedly lacunose; dorsally deeply grooved

along entire length or only apically; rarely in rosettes; green to straw-coloured or

whitish, very rarely tinged with purple . . . A 1.2. group Vesiculosa:

118

HEPATOPHYTA: Ricciaceae

11a Thalli large and very wide, 5-15 x 3.5— 5.5(— 8) mm; when dry, yellowish to

straw-coloured or white; spores 100—1 50(— 160) pm diam., with 8-12 alveoli

across distal face, wing thin, ± 10 pm wide:

12a Thalli straw-coloured when dry; deeply grooved along entire length; pitted in

older parts only; spores with alveoli on distal face 10-15 pm wide . . 5. R. bullosa

12b Thalli white when dry; mostly only apically grooved; honeycomb-pitted dor-

sally; spores with alveoli on both faces larger, up to 20 pm wide . . . 6. R. garsidei

1 1 b Thalli narrower, up to 1 2 x 2. 5-3.0 mm; when dry, greyish white to yellowish; spores

88-112 pm diam., with 5-8 alveoli across distal face, wing narrow, width 3-5 pm:

13a Thalli rarely in rosettes; antheridial necks inconspicuous, hyaline; apical

stolons not formed; widespread in summer rainfall areas 7. R. volkii

13b Thalli not in rosettes, somewhat linear; antheridia with conspicuous purple

necks (Figure 33B); apical stolons formed; very rare, only known from Knysna

Dist 8. R. rubricollis

2b Dorsal epidermis other than thin-walled, single-layered flat cells interrupted by air pores:

14a Dorsal epidermis with thick-walled cells, lacking chlorophyll; air pores surrounded

by superimposed ring of smaller, thin-walled cells; thallus narrowly grooved, acutely

winged; scales rounded, persistent, large, reaching thallus margins; spores single

. . . D. subgenus Chartacea: 14. R. schelpei

14b Dorsal epidermis with cellular outgrowths of very tall, hair-like pillars; air pores sur-

rounded by radially arranged wedge-shaped cells; thallus broadly grooved, obtuse-

ly winged; scales triangular, persistent, large, filamentous apices extending beyond

thallus margins; spores remaining in globular to tetrahedral tetrads (Plate 16C, D)

. . . C. subgenus Pannosae: 13./?. tomentosa

lb Thalli covered by dorsal ‘epithelium’ of echlorophyllose cells in 1 or several strata; air

pores numerous, small, regular intercellular spaces; assimilation tissue compact, in ver-

tical rows of chlorophyllose cells separated by mostly very narrow interstitial air

canals; scales small to large; spore tetrads separating at maturity; habitat often xeric,

sometimes mesic . . . E. subgenus Riccia:

15a (15b: p. 121) Epithelial cells closely associated, in one or two layers, top cells globose,

mammillose or pyriform, outer walls (or cells) often collapsing, generally orientated

egularly and in parallel rows running from median groove across to margin; scales

small to large, rounded . . .El. section Riccia :

16a Thalli with cilia along margins, occasionally also present over sporangia; ventral

scales not conspicuous; sometimes flanks dark purple ... El. 1. group Ciliatae:

17a Thalli medium-sized to large, branches up to 12 x 4 mm; cilia white when dry,

300(-400) pm long, finely granular (Figure 43C), absent over sporangia; spores

straw-coloured, with wing 10 pm wide, slightly undulating 18./?. natalensis

17b Thalli smaller, less than 8.0 x 1.5 mm; cilia hyaline, dry or wet, long or short;

spores brown to black, with or without wing:

18a Cilia generally quite sparse, 250(-400) pm long, finely granular, absent over spo-

rangia; scales small, purple; flanks green; spores with wing ± 7.5 pm wide;

distribution in FSA area restricted to winter rainfall region of southwestern

Western Cape 1 6. /?. crozalsii

18b Cilia crowded, dense, variously long, not granular, present over sporangia; flanks

dark purple; spores mostly wingless; widespread in summer rainfall areas:

19a Thalli 5-6 x 0.9-1. 5 mm; cilia straight to slightly flexuose, up to 950 pm long,

smooth; spores 100-120 pm diam., ornamentation reticulate, alveolar walls

heavily encrusted with papillae (Plate 17A, B) 15./?. trichocarpa

HEPATOPHYTA: RlCCIACEAE

1 19

19b Thalli small, \^\ x 0. 6-0.8 mm; cilia arched (Figure 42C), up to 300 pm long,

channelled and finely striate; spores 80-90 pm diam., ornamentation reticulate,

alveolar walls mostly smooth 17./?. microciliata

16b Thallus margins not ciliate, marginal cells enlarged or not; ventral scales small to

large ... El. 2. group Mammillatae:

20a Thallus margins apically with row of mammillate cells (Figure 43K) up to 150 pm

long; scales small, not extending to thallus margins, violet to hyaline . . 19./?. mammifera

20b Thallus margins glabrous; scales larger, extending to margins or projecting above,

hyaline or variously pigmented ... El. 3. group Squamatae:

21a Scales not conspicuous, hyaline or partly hyaline; thallus margins hyaline; groove

narrow and deep along entire length of thallus; dorsal epithelium generally with

some cell walls thickened:

22a Dorsal epithelial and subepithelial cells always with markedly thicker walls

(Figure 44E); thalli light green, appearing almost waxy; flanks green; spores

polar, dark reddish brown to black, proximal face densely granulate (Plate 19F);

widespread (nearly cosmopolitan), but rare in FSA area 20. R. sorocarpa

22b Dorsal epithelial cells with walls sometimes thicker; thalli glaucous-green to silvery

grey-green; flanks dark red-brown; spores almost apolar, subglobular, dull dark

brown to nearly black, reticulate; endemic and common in summer rainfall

areas 21./?. atropurpurea

21b Scales large and conspicuous, pigmented, with or without hyaline border or entire-

ly hyaline to white; groove various; dorsal epithelial cell walls not thickened:

23a Scales dark, black or reddish black to deep violet, shiny; thallus size variable;

dorsally glaucous-green to green or purplish, rarely brown:

24a Thalli smallish to medium-sized; in section once to twice wider than thick;

flanks steeply rising:

25a Thalli medium-sized; dorsally entirely glaucous-green; scales with crenate edges,

projecting above thallus margins (Figure 46H); when dry, rather dull black;

pores golden brown, wingless, densely papillate 22. R. okahandjana

25b Thalli smallish; glaucous-green, rust-brown along margins and proximally;

scales with entire edges appressed, not projecting above thallus margins,

shiny when dry or wet; spores light brown to dark brown, winged, incom-

pletely reticulate 26. R. nigrella

24b Thalli medium-sized to large; in section 2. 5-5.0 times wider than thick; flanks

sloping obliquely:

26a Thalli large, up to 15 x 5 mm; margins winged, overhanging; spores sub-

globular, apolar, ornamentation reticulate with thin, high alveolar walls . . .

23. R. congoana

26b Thalli medium-sized to large, up to 15 x 3( — 4) mm; margins attenuate, not

overhanging; spores triangular-globular, polar, alveolar walls thick, low:

27a Thalli quite fleshy; scales imbricate, clasped together along midline when

dry (Figure 48A); spores 90-125 pm diam., distal face with short spiralling

ridges, proximal face almost smooth, with scattered pores; distribution in

FSA area restricted to winter rainfall regions of Cape 24. R. limbata

27b Thalli mostly thinner; scales imbricate to proximally more widely spaced;

when dry, opposite scales meeting or not, never clasped together; spores

72-82 pm diam.; distal face with alveoli in more or less concentric rings;

proximal face completely or incompletely reticulate; widespread in summer

rainfall regions, but not common 25. R. angolensis

120

HEPATOPHYTA: RlCCIACEAE

23b Scales other than black, variously coloured or white; thalli small to medium-

sized; dorsally green to yellow-green, white or brownish:

28a Scales brown or various shades of pink to red:

29a Thallus margins and scales brownish yellow; idioblasts (enlarged cells with

brown contents) present throughout thalli (Figure 50K); spores vermiculate;

species very rare in FSA area 27. R. macrocarpa

29b Thallus margins not brown; scales pink to dark red; idioblasts absent; spores

reticulate:

30a Thalli very small, 1 .5— 2.5(— 3) x 0. 7-1.0 mm; bottle-green, tumid; scales

regular, appressed, dark red, white-bordered; spores 60-78 pm diam., tri-

angular-globular, polar; distribution restricted 28. R. pottsiana

30b Thalli medium-sized; bright green or light green to whitish; scales wine-red

or rose-pink; spores 80-105 pm diam., globular to subglobular, apolar; dis-

tribution widespread:

31a Thalli 7-9 x 1.2-1. 6 mm; bright green, turning grey-green; scales dark red,

shiny, with narrow hyaline border; monoicous; spores red to black, sub-

globular, periphery with prominent projections, cogwheel-like in profile

29. R. runssorensis

31b Thalli up to 12 x 1.0-2. 5 mm; pale green but white along margins; scales

wavy, rose-pink with wide hyaline border; dioicous; spores rare, light

brown, periphery with low projections 30. R. rosea

28b Scales predominantly white or hyaline, often encrusted with calcium deposits,

wavy or appressed:

32a Scales large, up to 1250 x 750 pm, irregularly wavy to frilly, closely imbri-

cate; thalli mostly 8-9 (rarely up to 12) x 1.5-2.0(-4) mm; apically grooved;

dorsally green, turning white and spongy over sporangia:

33a Thalli in rosettes or gregarious; spores with 10-12 round to angular alveoli

across diam. of distal face; widespread and quite common .... 31 . R. albolimbata

33b Thalli not in rosettes; spores with 14-20 small, deep alveoli across diam. of

distal face; quite rare, distribution apparently restricted to Northern, West-

ern and northern part of Eastern Cape 33. R. albornata

32b Scales smaller, up to 850 x 500 pm, mostly appressed and regular, imbricate;

thalli generally rather smaller, 7-8 x 0.7-2. 0(-4) mm; grooved apically or

along almost entire length; dorsally mat or shiny:

34a Thalli deeply grooved along most of length; dioicous; spores apolar or polar:

35a Dorsally mat, grey-green; compact; dorsal epithelial cells thick-walled,

collapsed, in regular honeycomb pattern; scales tightly appressed (Figure

55B), base silvery purple-grey; spores apolar, wingless; fairly widespread

32. R. argenteolimbata

35b Dorsally glistening, light green to green; finely spongy; dorsal epithelial

cells thin-walled, not in regular pattern; scales apically wavy, soon

appressed; spores polar, winged; distribution restricted to eastern moun-

tainous regions 34. R. montana

34b Thalli only apically grooved; monoicous; spores polar:

36a Thalli with wide, shallow groove; 8x4 mm; dorsally very heavily encrusted

with calcium deposits; air pores large, regular; scales white; spores finely

reticulate 35. R. alboporosa

HEPATOPHYTA: RICCIACEAE

121

36b Thalli narrowly grooved; up to 5 x 1-2 mm; dorsally with fine calcium

deposits; air pores small to large, irregular; scales bicoloured, with deep

purple base; spores more coarsely reticulate 36. R. bicolorata

15b Epithelial cells in free-standing 2-5(-6)-celled, uniseriate pillars not regularly orien-

tated, top cells variously shaped, soon collapsing; scales small to large, mostly rounded

and smooth-margined, rarely triangular and dentate or apically filiform . . . E2. section

Pilifer:

37a Dorsal pillars short, often shorter than 200 pm, consisting of 2 or 3(4) cells, mostly

wider than long, tapering or not tapering:

38a Dorsal pillars tapering; air canals rather wide, width up to 100 pm:

39a Spores narrowly winged, wing ± 5 pm wide; ornamentation on distal face not ela-

borate, especially not on proximal face where often reduced to simple projections and

stipplings; widespread 44. R. albovestita

39b Spores wide-winged, wing up to 10 pm wide; distal face elaborately ornamented;

very rarely found:

40a Thalli large, up to 10.0 x 2. 5-3. 8 mm; scales hyaline 42. R. hantamensis

40b Thalli small, 3. 5-5.0 x 0.9-1. 5(-2) mm; scales red 41./?. alatospora

38b Dorsal pillars not tapering; air canals narrow:

41a Thalli quite large, 6-10 x 3-4 mm; broadly ovate to obovate; in section 3-4 times

wider than thick; flanks sloping obliquely; distal spore face with 10-14 alveoli

across diam., sometimes with central papilla or short radiating ridges . . 46. R. concava

41b Thalli smaller, up to 8 x 1-2 mm, ligulate to ovate; in section as wide as, to twice

wider than thick; flanks steep; spores variously ornamented:

42a Branches frequently simple, long and narrow; spore distal face with 5-7 large,

incomplete alveoli across diam., often with central boss 39. R. elongata

42b Branches mostly several times furcate; spore distal face with more than 7 smaller

alveoli across diam., lacking central boss:

43a Branches apically rounded, margins not tumid; dorsal cell pillars only 70-105

pm long; proximal spore face granulate 37. R. pulveracea

43b Branches apically keeled to wedge-shaped, margins somewhat tumid; dorsal

cell pillars up to 180 pm long; proximal spore face reticulate:

44a Dorsal pillars with top cell mammillose; distal spore face with ridges gener-

ally forming a central cross (Plate 25E); distribution restricted to southeastern

Northern and northern and north-central Western Cape 38. R. furfuracea

44b Dorsal pillars with top cell globose; distal spore face with ± 8 angular, irregular

alveoli across diam.; distribution apparently restricted to Lesotho

40. R. trachyglossum

37b Dorsal pillars tall, more than 200 pm and up to ± 450 pm (rarely 1000 pm) long, con-

sisting of (3-)4— 6 narrow, elongated cells ( 1 .5— )2— 3 (or more) times longer than wide:

45a Dorsal surface of thalli generally somewhat velvety or furry when fresh; emerald-

green to lighter green; cell pillars gradually tapering to narrower apical cell:

46a Scales rounded, wavy, large, ± 1500 x 600-900 pm, margin entire; thalli emerald-

green; basal cells of pillars almost equally long, walls somewhat thickened;

spores polar, ornamentation finely or coarsely reticulate 52. R. simii

46b Scales triangular, very large, up to 1800 pm long; basal cells of pillars variably

long, walls not thickened; spores variously ornamented:

47a Triangular scales with dentate margins (Figure 7 IE); dorsal pillars up to 450 pm

long; spores papillose; not rare, but distribution restricted to western Northern

Cape and Western and Eastern Cape 50. R. villosa

122

HEPATOPHYTA: RlCCIACEAE

47b Triangular scales with filamentous apices (Figure 72G); dorsal pillars up to 1000

pm long; spore ornamentation incompletely reticulate; very rare 51./?. hirsuta

45b Dorsal surface of thalli rarely velvety or furry; steel-grey to bright green or oliva-

ceous green; cell pillars not, or hardly tapering:

48a Thalli dorsally steel-grey; tall cell pillars (up to 450 pm long) like slivers of glass,

often interlocking over groove; branches up to 9 mm long; scales large and bil-

lowing, basal cell walls appearing ‘stretched’; distal spore face with a few short,

well-spaced, radiating, central ridges; proximal spore face incompletely reticu-

late and granulate 49. R. vitrea

48b Thalli dorsally olivaceous green or crystalline; cell pillars shorter (mostly less

than 350 pm long), not interlocking, or if so, only temporarily toward apex;

branches mostly less than 8 mm long; scales smaller and not billowing; spore

ornamentation on distal face reticulate or with several, long, thick, radiating

ridges; on proximal face, not granulate:

49a Dried thalli with brown, parchment-like flanks, proximally almost denuded of

scales; wet thalli velvety, olivaceous green; distal spore face with thick radiating

ridges 47. R. albomarginata

49b Dried thalli frequently with somewhat purple flanks; wet thalli rather crystalline,

bright green or purplish green:

50a Thalli in section 1.5 times to nearly twice wider than thick; sides tightly in-

flexed when dry 48. R. namaquensis

50b Thalli in section 2-4 times wider than thick; sides incurved when dry:

51a Cells in dorsal pillars mostly somewhat constricted in the middle, ampulla-

shaped; spores 90 — 95( — 1 05 ) pm diam.; distal face with several radiating

ridges; distribution restricted to eastern mountains 45. R. ampullacea

51b Cells in dorsal pillars not constricted; spores 70-80(-90) pm diam.; orna-

mentation with numerous small alveoli; distribution restricted to western

and northern Western Cape 43 . R. parvo-areolata

A. Subgenus Ricciella

Ricciella (A. Braun) Rchb., Der Deutsche Botaniker, Vol. 1. Das Herbarienbuch: 23 (1841), fide

Grolle: 426 (1983b). Lectotype: R. fluitans L.

Spongodes (Nees) O H. Volk: 456 (1983). Type: not designated.

Thalli smallish to large; terricolous, rarely aquatic. Scales ventral, small, mostly evanescent.

Dorsal epidermis chlorophyllose; air pores scattered, soon enlarging, often becoming lacunose.

Assimilation tissue with large, polyhedral to irregular air chambers.

Sporangia immersed or bulging ventrally; vertical or rarely oblique. Spores smallish to medi-

um-sized to large; tetrads separating at maturity.

Al. Section Spongodes Nees, Naturgeschichte der Europaischen Lebermoose 4: 391 (1838).

Lectotype: R. crystallina L. emend. Raddi, fide Grolle: 248 (1976).

Thalli medium-sized to large, rarely heterothallic with small male gametophytes; terricolous.

Scales ventral, small, evanescent.

HEPATOPHYTA: Ricciaceae

123

Dorsal epidermis chlorophyllose; air pores soon large, lacunose. Assimilation tissue with large

polyhedral air chambers.

Sporangia mostly immersed, sometimes bulging somewhat ventrally or dorsally. Spores medi-

um-sized to large; separating at maturity.

Two groups are recognized within this section: Group Crystallina and Group Vesiculosa.

Al.l. Group Crystallina

Thalli mostly in rosettes or partial rosettes; dorsally becoming lacunose.

1. Riccia crystallina L. emend. Raddi in

Opuscoli Scientifici. Bologna 2: 351, 353

(1818); Steph.: 369 (1898); Sim: 14 (1926);

Jovet-Ast: 459 (1964); Jovet-Ast: 82 (1966); Na-

Thalang: 107 (1980); Jovet-Ast: 340 (1986);

Perold: 58 (1991c); R.M.Schust.: 494 (1992b);

Jovet-Ast: 229 (1993). Type: Micheli, PA. 1729.

Nova plantarum genera, tab. 57, fig. 3, lecto.,

Riccia 0:2. n:l (FI, typo.) fide Perold (1992b).

R. plana Taylor: 414 (1846); Steph.: 368 (1898);

A.V.Duthie & Garside: 111 (1937); Hassel de Menendez:

223 (1963); S.W.Amell: 40 (1963a). Type: Australia, Swan

River, Drummond s.n., 1843 (K, holo.; MEL, iso.).

Thalli medium-sized, isolated or crowded, or

in incomplete or complete compact rosettes,

15-20(-25) mm across; glaucous-green or grey-

ish green, crystalline, not pitted apically, only

more proximally becoming slightly spongy;

when dry, bluish grey, finely spongy, margins

raised, not inflexed. Branches 2 or 3 times fur-

cate, shortly to rather more deeply divided,

often crowded and overlapping laterally to

moderately divergent, obcuneate, 5-7 x (2-)3-4

mm, 0.6-0. 8(-1.0) mm thick, in section 3-5

times wider than thick, apex rounded, truncate

or shortly emarginate; groove only present dis-

tally, shallow, thallus margins rounded, obtuse;

flanks sloping obliquely, green; ventral face

gently rounded to flat, green. Scales ventrally

present near apex only, minute, difficult to

detect, hyaline.

Dorsal epidermis not areolate, cells when

turgid, almost globular, shiny, single or tiered in

pairs, laterally rather loosely connected, 37.5-

50.0 x 50-60 pm; air pores apically small and

obscured, soon widening as air chambers en-

large, eventually leaving them more exposed.

Assimilation tissue 400-600 pm thick, air cham-

bers apically narrow, slit-like, wide toward base,

polygonal, bounded by unistratose walls of

chlorophyllose cells; storage tissue occupying ±

4 ventral cell layers of thallus. Figure 27A-F.

Monoicous. Antheridia sunken in rows along

dorsal face of lobes, necks colourless, ± 200 pm

long. Archegonia embedded along middle of

lobes, necks purple-brown, ± 250 pm long.

Sporangia abundant, bulging slightly ventrally,

crowded. Spores 65-80(-85) pm diam., triangu-

lar-globular, polar, pale yellow to light brown,

semitransparent; wing up to 7.5 pm wide, usu-

ally broader at marginal angles, notched or with

a round pore, 5 pm across, margin finely crenu-

late, sometimes erose; ornamentation regularly

reticulate, similar on 2 spore faces; distal face

highly convex, with 8-10 usually complete,

round or oval alveoli across diam. of spore,

7.5-10.0 pm wide, alveolar walls thin and low,

raised at nodes into spinous or truncate process-

es, ± 7.5 pm high, tips often bifid or even trifid;

proximal face with triradiate mark distinct, its

arms ± 5 pm high, often interrupted for short

sections, dotted with granules, each of 3 facets

with ± 20 rounded or angular alveoli, 5. 0-7. 5

pm wide, walls thin and low, raised at nodes

into spinous processes, granular or divided at

tips. Chromosome number : n = 8 (Mehra 1977;

Jovet-Ast 1986; Bornefeld 1989). Plate 1 1C, D;

Perold (1989e: fig. 36.1-6).

Although Micheli (1729) had clearly distin-

guished between two species, Linnaeus (1753)

HEPATOPHYTA: Ricciaceae

125

united into one species ‘ Riccia minima et

minor’ and named the combination R. crystalli-

na. Years of confusion followed until Jovet-Ast

(1964, 1966) distinctly defined R. crystallina

and R. cavernosa.

Riccia crystallina is a subcosmopolitan

species. It is widely distributed in southern

Africa, but has been fairly rarely collected,

except in the southwestern part of Western

Cape, where it is relatively common. It is found

on damp, sandy or clayey soils or on mud, at the

edges of ponds, at streambanks, on cultivated

ground in gardens and along footpaths. Map 11.

This species can be distinguished from R.

cavernosa (no. 2) by the finer, compact texture

of the thallus, its crystalline appearance and

glaucous-green colour. The spores are highly

ornamented, somewhat ‘prickly’ in appearance,

and have eroded wing margins. It is, however,

uncertain what Sim’s (1926) concept of the

species was. Duthie & Garside (1937) remarked

that Sim’s illustration of R. crystallina , fig. A, is

of R. cupulifera and that the spore depicted in

fig. D is of R. curtisii, since it is in a tetrad.

Duthie’s note enclosed with the specimen,

Garside 6, a bequest from Sim’s herbarium and

identified by him as R. crystallina, reads:

‘Possibly a mixture of R. crystallina1. and R.

curtisii. The only spores seen adhered in tetrads

and is characteristic of R. curtisii’. Riccia plana

was placed in synonymy under R. crystallina by

Jovet-Ast (1966); their relationship according

to Arnell (1953), had also been pointed out by

Garside, yet he (Arnell 1963a) described both.

Vouchers: S.W. Arnell 189 (BOL); Duthie

5006 (BOL); Koekemoer 103a (PRE); Morley

308 (PRE); S.M. Perold 455 (PRE).

2. Riccia cavernosa Hoffm. emend.

Raddi in Opuscoli Scientifici. Bologna 2: 353

(1818); Jovet-Ast: 459 (1964); Jovet-Ast: 82

(1966); Jovet-Ast: 342 (1986); Na-Thalang:

108 (1980); Vianna: 71 (1981); Perold: 59

(1991c); R.M. Schust.: 487 (1992b); Jovet-Ast:

231 (1993). Type: Allemagne. In terra limosa,

ad piscinas. [Herb. Hoffm., not at MW, fide

Jovet-Ast: 342 (1986)].

R. cavernosa Hoffm.: 95 (1795).

Ricciella rautanenii Steph.: 374 (1895a); A.V.Duthie &

Garside: 20 (1939); S.W.Arnell: 40 (1963a). Type:

Hereroland, Tsoachaub River, Rautanen (G).

Thalli medium-sized to large, in complete,

regular rosettes up to 30 mm across; bright

grass-green to yellowish green, often becoming

tinged with red along margins, older parts

lacunose (cavernose); when dry, margins not

inflexed, yellowish, spongy. Branches repeated-

ly furcate, shortly to deeply divided, nearly par-

allel or crowded and overlapping, oblong-obo-

vate or obcuneate, (2-)4-8 x 1.5-2.5(-4) mm,

up to 1 mm thick, in section 1 .5— 2.5( — 4) times

wider than thick, apex obtusely rounded, short-

ly emarginate; groove generally only distally

present, shallow, thallus margins rounded,

obtuse; flanks obliquely sloping; ventral face

rounded, green. Scales absent or evanescent.

Dorsal epidermis areolate, gently domed over

each air chamber, cells 4- or 5(6)-sided, walls

slightly bulging, up to 80-105 x 50-55 pm, in

between some scattered conical cells projecting

vertically, 50-60 x 37.0-47.5 pm; air pores when

young, generally somewhat obscured, with radi-

ally arranged surrounding cells soon enlarging

and becoming lacunose (cavernose). Assimi-

lation tissue up to 800 pm thick, air chambers

generally in a single storey, appearing to be several

storeys in section, because of obliquely sloping

cavities, bounded by unistratose walls of chloro-

phyllose cells; storage tissue occupying ventral

part of thallus. Figure 27G-M.

Figure 27. — A-F, Riccia crystallina: A, complete rosette; B, partial rosette; C, c/s epidermal cells and assimilation tis-

sue; D, epidermal cells from above; E, h/s assimilation tissue, air canals (stippled); F, c/s branch. G-M, R. cavernosa: G,

complete rosette; H, partial rosette; I, c/s epidermal cells and assimilation tissue; J, dorsal epidermis forming ‘dome’ over

larger air chamber; K, several epidermal ‘domes’ and air pores (hatched) from above; L, h/s through air chambers (stippled);

M, c/s thallus. A, D-F, Koekemoer J03; B, S.M. Perold 2428', C, S.M. Perold 455; G-I, L, Arnold 4323'. J, K, M, S.M. Perold

453. Scale bars: A, B, F-H, M, 1 mm; C-E, I-L, 50 pm. Artist: J. Kimpton.

126

HEPATOPHYTA: RlCClACEAE

Monoicous. Antheridia sunken in a row

along length of thallus, with colourless necks

projecting from pits in the surface. Arche gonia

in deeply embedded rows, with purple necks

not prominent. Sporangia protruding somewhat

ventrally as dark bulges, numerous, crowded.

Spores 85—1 10(— 1 15) pm diam., triangular-

globular, polar, reddish brown or almost black,

semitransparent to opaque; wing 5 pm wide,

somewhat broader at marginal angles, some-

times notched or porate, margin finely crenulate

or serrulate, occasionally erose; ornamentation

with irregular ridges, complete alveoli rare, dis-

similar on 2 spore faces; distal face convex,

centre prominently ridged, irregularly 2 or 3

times branched, ridges short and low toward

margin; proximal face with triradiate mark and

apex distinct, simple or branching or anasto-

mosing ridges occasionally uniting to form

mostly incomplete alveoli, quite variable.

Chromosome number: n = 8 (Na-Thalang 1980;

Jovet-Ast 1986; Bomefeld 1989). Plate 1 IE, F;

Perold (1989e: fig. 37.1-6).

Riccia cavernosa is an almost cosmopolitan

species. It is also widely distributed in southern

Africa, where it is found on alluvial mud or on

damp, sandy soil in Namibia, Botswana,

Northern Province, North-West, Mpumalanga,

Free State, KwaZulu-Natal, Lesotho, and

Northern, Western and Eastern Cape. Map 12.

The species can be recognized by the large,

mostly regular, yellowish green rosettes, often

tinged with red along the thallus margins; the

spores are characteristically bi- or trichoto-

mously ridged on the distal face.

The type specimen of R. cavernosa was not

seen, but Jovet-Ast’s (1964, 1966) detailed

descriptions, illustrations and measurements of

the thalli and the various patterns which the

sculpturing of the spores can assume, leave no

doubt that the southern African specimens have

been correctly referred here. Riccia rautanenii

Steph. was placed in synonymy under R. caver-

nosa by Jovet-Ast (1964) and southern African

specimens were seen by her. The R. chrystalli-

na (sic) spores illustrated by Arnell (1963a)

indicate that he was describing R. cavernosa , a

mistake commonly made until Jovet-Ast’s

(1964, 1966) thorough investigations clarified

the matter.

Vouchers: Acocks CH3602 (PRE); Kock 934

(PRE); S.M. Perold 363 (PRE); Schelpe 3907

(PRE); Volk 81/228 (M, PRE).

3. Riccia moenkemeyeri Steph., in

Botanische Jahrbticher 8: 95 (1886b); Steph.:

372 (1898); E.W.Jones: 211 (1957); Vanden

Berghen: 189 (1972); Perold: 19 (1992a). Type:

Niger Gebiet, Alt Calabar in terra, leg.

Moenkemeyer N3, 11-10-1884 ( G024384 ,

holo.!; S, iso.).

R. abrwrmis Steph.: 213 (1891); Steph.: 364 (1898).

Type: Kamerun, Bateki, leg. P Dusen 125, 17 Oct. 1890 (G).

?R. chevalieri Steph.: 116 (1912); Steph.: 1 (1917).

Type: Central African Republic, Haut-Oubangui, Plateau

des Ungourras, 650 m, Nov. 1902, leg. Chevalier, ex Herb.

Corbiere.

Ricciella undulata S.W.Amell: 105 (1952). Type: Africa

occidentalis, Sierra Leone, Freetown, stream-side above

Calabar Point, S. W. Arnell 2252 (S).

Thalli medium-sized to fairly large, in

crowded and often overlapping, gregarious

patches; glaucous-green, turning white over

older parts and along undulating margins,

sometimes with purple-red band on inner side,

only becoming pitted towards margins and

HEPATOPHYTA: RlCClACEAE

127

proximally; when dry, concave dorsally, mar-

gins apically incurved to indexed or somewhat

recurved. Branches once to several times fur-

cate, closely to moderately divergent, oblong to

ovate, 9— 10(— 12) x 1 .6—2. 4 mm, 0.8 mm thick

medianly, thinner toward margins, in section

2-3 times wider than thick, apex rounded to

subacute, emarginate; groove distally deep,

becoming shallow to flat or concave proximal-

ly, thallus margins rapidly thinning, acute,

winged and attenuate, ultimately consisting of a

single row of echlorophyllose cells; flanks

green to purple-red below, rather steep, then

abruptly sloping obliquely, becoming white

toward margins; ventral face rounded, green.

Scales mostly quite firmly attached to flanks

and difficult to detach, not extending to thallus

margins, rather distant, dark wine-red and shiny

or hyaline.

Dorsal epidermis with numerous small,

slightly domed to flat areolae over individual air

chambers, enlarging toward margins and proxi-

mally, sometimes rupturing, cells polygonal,

42-55 x 20-37 pm; air pores encircled by small-

er companion cells. Assimilation tissue 350- 400

pm thick, air chambers in one storey, but often

appearing to be secondarily partitioned, bounded

by unistratose walls of chlorophyllose cells; stor-

age tissue occupying ventral part of thallus, cells

with small spaces wedged in between. Figure 28.

Monoicous. Antheridia sunken in a row

along groove, hyaline necks emerging from

small depressions. Archegonia deeply embedded

along groove, necks sloping toward apex of thal-

lus, difficult to detect from above. Sporangia

obliquely orientated and protruding ventrally,

single or 2 adjacent or serially arranged, sub-

spherical. Spores (65— )68— 75 (-85) pm diam.,

Figure 28. — Riccia moenkemeyeri. A-C, thallus: A,

dorsal face, with rows of antheridial necks; B, ventral face;

C, when dry. D, air pore (hatched), dorsal and subdorsal

cells (stippled lines) enclosing air chamber; E, c/s branch;

F, c/s showing air chambers; G, 1/s sporangium with for-

ward-sloping archegonial neck; H, chromosomes. A-H,

S.M. Perold 2603. Scale bars: A-C, E, G, 1 mm; D, F, 50

pm; H, 1 pm. Drawings by G. Condy; karyotype by T.

Bomefeld (pers. comm.).

128

HEPATOPHYTA: Ricci ACEAE

Plate 12. — Spores. A, B, Riccia moenkemeyeri: A, distal face; B, proximal face. C, D. R. cupulifera; C, dis-

tal face; D, proximal face. E, F, R. bullosa: E, distal face; F, proximal face. A, B, Sim 9072', C, S.M. Perold 2371;

D. Schelpe 7787 (BOL); E, F, S.M. Perold 467. A, B, D, x 700; C, E, x 600; F, x 500.

HEPATOPHYTA: Ricciaceae

129

triangular-globular, polar, light tan to yellowish

brown, semitransparent; wing ± 5 pm wide,

somewhat broader at generally perforated mar-

ginal angles, margin finely crenulate; ornamen-

tation reticulate, but completely dissimilar on 2

spore faces; distal face convex, with (8)9 or 10

alveoli across diam., 8— 10(— 12) pm wide, occa-

sionally incompletely separated, walls low, cover-

ed with fine granules and slightly raised into

papillae at nodes; proximal face lacking a trira-

diate mark, each of 3 facets with up to ± 100

tiny, mostly less than 2.5 pm wide, shallow, but

clearly defined alveoli, the walls forming a fine

network. Chromosome number, n = 9 (Bor-

nefeld pers. comm, on S.M. Perold 2603 ); n = 8

(Jovet-Ast 1969) Plate 12A, B.

Riccia moenkemeyeri is a tropical African

species, known from Sierra Leone (as R. undu-

lata), Angola, Cameroon, the Congo Basin

[Region du Lac Moero (Vanden Berghen 1972)],

Gambia, Ghana, Ivory Coast, Malawi, Niger,

Rwanda, Tanzania, Zimbabwe, and now also

with outliers into the Northern Province and

Gauteng, southern Africa (Map 13). Its presence

on Fernando Po, as reported by Stephani (1887)

for the type specimen, Moenkemeyer 3, must

have been a mistake, as the locality given on the

label is Calabar, Niger, which is confirmed in

Species hepaticarum (Stephani 1989).

The species grows in damp places, on rich

loamy soil, mostly near streams and in associa-

tion with other Riccia species (in southern

Africa) such as R. stricta, R. atropurpurea and

with Exormotheca pustulosa.

Riccia moenkemeyeri is characterized by a

more or less persistent dorsal epidermis which

is marked out into small areolae, each with a

small central air pore; by numerous narrow air

chambers, appearing to be in more than one

storey; by undulating thallus margins which ter-

minate in a single row of hyaline cells; by

obliquely orientated sporangia and a highly dis-

tinctive spore ornamentation with 8-10 large

alveoli on the distal face and numerous tiny

alveoli on the proximal face, which lack a trira-

diate mark.

0 R. cupulifera

Vouchers: Condy 22, 23\ S.M. Perold 2603.

4. Riccia cupulifera A. V.Duthie in Trans-

actions of the Royal Society of South Africa 24:

116 (1937); S.W.Arnell: 39 (1963a): Perold: 60

(1991c). Type: Cape, Stellenbosch, A.V. Duthie

5007 (BOL, syn.!).

Plants heterothallic, male thalli very small,

simple or furcate; rather light green to yellow-

green; female thalli smallish to medium-sized,

crowded or in incomplete to complete rosettes,

20-25 mm across, or scattered and in so-called

‘butterfly’ shapes; bright green to yellowish

green, soon becoming pitted and basally lacu-

nose; when dry, greenish yellow and slightly

wrinkled, spongy, margins not inflexed. Branches

in female thalli, 2 or 3 times furcate, shortly to

deeply divided, almost overlapping or closely to

moderately divergent, oblong to obcuneate, up to

7 x 2.0-3. 5 mm, 0.7-1. 0(-l. 5) mm thick, in sec-

tion ± 3 times wider than thick, apex rounded,

truncate or emarginate; groove distally short and

shallow, otherwise flat, thallus margins obtuse,

rounded; flanks slightly bulging to somewhat

obliquely sloping; ventral face rounded to flat,

green. Scales ventral toward apex, minute,

evanescent, rarely observed. Plate 13 A.

Dorsal epidermis areolate, slightly domed

over each air chamber, cells polygonal, variable

130

HEPATOPHYTA: Ricciaceae

Plate 13. — Thalli. A, Riccia cupulifera, rosette; B, R. volkii, crowded branches; C, R. stricta, overlapping

branches; D, R. purpurascens, overlapping branches; E, R. tomentosa, hairy branches. F, R. schelpei, deeply

grooved branches. A, S.M. Perold 2395; B, S.M. Perold 2472; C, S.M. Perold 2524; D, S.M. Perold 2386; E,

S.M. Perold & M.J.A.W. Crosby 2157; F, S.M. Perold 1422. Scale bars: A-F, 1 mm.

HEPATOPHYTA: Ricciaceae

131

in size, 60-130 x 50-75 pm, in between with

scattered, erect, rounded cells, mostly ± 40 pm

long, more numerous toward apex and around

bases of antheridial and archegonial necks; air

pores small at apex, rapidly enlarging by rup-

ture of surrounding, radially arranged cells,

proximally becoming as wide as air chambers.

Assimilation tissue 500-800 pm thick, air

chambers polyhedral, in one storey, narrow in

younger parts of thallus, wider proximally,

bounded by unistratose walls of chlorophyllose

cells; storage tissue occupying ventral 3 or 4(5)

cell layers of thallus. Figure 29.

Dioicous. Antheridia very numerous, sunken

in a row along middle of mostly small male

thalli, necks hyaline, ± 200 pm long. Arche-

gonia scattered along median area of female

plants, necks purple. Sporangia bulging dorsal-

ly, from above dark spore mass visible through

overlying tissue, which gradually shrinks away,

exposing cup-like hollows, becoming confluent

along middle of older thalli and containing large

numbers of liberated spores. Spores 90-1 15(— 122)

pm diam., triangular-globular, polar, light

brown to darker brown, semitransparent; wing

thick, up to 7.5 pm wide, notched or perforated

at marginal angles, margin Finely crenulate,

with row of granules along edge; ornamentation

foveolate, with deep-set, rounded alveoli on

both spore faces, similar to rather dissimilar;

distal face often highly convex, with 12-13

small alveoli or fovea across diam., 2. 5-5.0 pm

wide, walls high, up to 5 pm wide, warty or

knobbly, raised into truncate processes at nodes,

borders often joining to form short, undulating

or radiating ridges; proximal face with triradiate

mark very prominent, its arms up to 7.5 pm

wide, even wider at join with wing, dotted with

fine granules, each of 3 facets with ± 35 small,

deep, rounded alveoli, less than 5 pm wide,

sometimes adjacent ones confluent, walls thick-

ened and raised, especially at nodes, granulate

to papillate. Chromosome number: n = 8 (Bome-

Figure 29. — Riccia cupulifera. A, B, thallus: A, female in partial rosette; B, small male. C, 1/s of 2 antheridial necks;

D, epidermal cells and air pores (hatched) overlying air chambers seen from above; E, air pore (hatched) with surrounding

cells, only one of scattered, rounded cells shown, from above; F, c/s branch. A-C, S.M. Perold 2395 ; D-F, Oliver 8043.

Scale bars: A, B, F, 1 mm; C, E, 50 pm; D, 100 pm. Artist: J. Kimpton.

132

HEPATOPHYTA: RlCCIACEAE

feld 1989). Plate 12C, D; Perold (1989e: fig.

38.1-6).

Riccia cupulifera is endemic to southern

Africa, and widespread in the shrublands of the

western parts of Northern and Western Cape,

rare in the Free State and only found once in

Mpumalanga. Map 13.

The species grows on damp, sandy soil or on

mud, and can be distinguished from R. crystalli-

na (no. 1) and R. cavernosa (no. 2), the other

two rather similar species with spongy thalli, by

being dioicous and heterothallic, by the charac-

teristic ‘butterfly’ shape of young thalli, and by

never developing a reddish or purple tint on

exposure to the sun, as in R. cavernosa. The

spores can be recognized by the very prominent

arms of the triradiate mark on the proximal face,

the thick wing and foveolate ornamentation.

Vouchers: S.W. Arnell 303 (PRE); Duthie

5488 (BOL); Oliver 8053 (PRE); S.M. Perold

591 (PRE); Schelpe 7787 (BOL).

A 1.2. Group Vesiculosa

Thalli rarely in rosettes; mostly large and succulent.

5. Riccia bullosa Link ex Lindenb. in

Nova acta Academiae Caesareae Leopoldino-

Carolinae Germanicae Naturae Curiosorum,

Supplement 14: 1 19 (1829); Lehm.: 371 (1829);

Lindenb.: 441 (1836); Nees: 391, 433 (1838);

Gottsche et al.: 609 (1844-1847); Steph.: 377

(1898); Sim: 13 (1926); S.W.Arnell: 42 (1963a);

Perold: 131 (1991b); Perold: 61 (1991c). Type:

Cape, terrestris, ad montem tabularem versus

montum Leonio, Ecklon s.n. (STR, lecto.!).

R. crassa Nees ex Lindenb.: 119 (1829) nom. inval.

R. montaguensis S.W.Arnell: 308 (1952); S.W.Arnell:

44 (1963a). Types: Cape Province, Montagu, Bath Kloof,

near the caves, S. W. Arnell 714 (BOL!; PRE!), 741 (BOL!).

Thalli medium-sized to large, in crowded,

gregarious patches or scattered; apically light

green, soon turning straw-coloured, medianly

deeply grooved, laterally swollen to bloated,

with small, polygonal, domed alveoli, trans-

versely wrinkled, becoming proximally pitted

and spongy; when dry, rather deflated and with

folds across, sides not inflexed, margins scal-

loped. Branches once, occasionally twice fur-

cate, sometimes simple, shortly to deeply divid-

ed, moderately to widely divergent, broadly

ovate to oblong, 5-15 x 3. 5-5. 5 mm, 1.5-2. 5

mm thick, in section 2. 0-2. 5 times wider than

thick, apex obtuse to truncate, emarginate;

groove deep and narrow, sometimes split into

two by raised wedge of tissue, disappearing

toward base or at sporangia, thallus margins

obtuse, rounded, often overhanging; flanks

sloping obliquely; ventral face rounded to

keeled, green. Scales ventral, toward apex only,

vestigial, hyaline, in pairs.

Dorsal epidermis forming a domed roof over

each air chamber, cells 4-6-sided, 62-75 x

35^10 pm; air pores surrounded by 6 or 7

wedge-shaped, smaller and often thinner-walled

cells, breaking down with age and exposing air

chambers. Assimilation tissue 1000-1500 pm

thick, air chambers tall, mostly in one storey,

vertical or sloping obliquely, narrower toward

centre and apex, bounded by unistratose, chloro-

phyllose cell walls; storage tissue occupying

ventral part of thallus, cells angular, closely

packed, containing starch granules. Figure 30.

Dioicous. Antheridia sunken in 1 or 2

crowded rows along slightly raised central ridge

in groove, hyaline necks protruding from small

pits, up to 500 pm long. Archegonia embedded

in a row along groove, purple necks ± 300 pm

long. Sporangia crowded together, bulging dor-

sally, overlying tissue thinning and disintegrat-

HEPATOPHYTA: RlCCIACEAE

133

ing. Spores ( 100—) 1 30— 1 50(— 1 60) pm diam.,

triangular-globular, polar, yellow-brown, becom-

ing darker with age, semitransparent; wing thin,

undulating, up to 10 pm wide, often perforated

at marginal angles, margin finely crenulate,

occasionally partly erose; ornamentation reticu-

late, rather similar on two spore faces; distal

face with 10-12 rounded alveoli across diam.,

10-15 pm wide, sometimes larger and incom-

pletely separated by low, fragmentary ridges

radiating from central pillar, alveolar walls fine-

ly granular, 5 pm high, thin, generally becom-

ing higher and thicker over centre, raised at

nodes and often extending onto wing; proximal

face with triradiate mark consisting of thin

ridges up to 7.5 pm high, frequently joined by

alveolar walls, each of three facets with

1 3—1 8(— 25) rounded alveoli, 10-15 pm wide,

often incompletely separated and adjoining

ones confluent. Chromosome number: n = 8

(Bornefeld 1989). Plate 12E, F; Perold (1989e:

fig. 39.1-6).

Riccia bullosa is endemic to southern Africa

and is found at seepages or on damp sandy soil

under brush or at granite, basalt or sandstone

outcrops in the western parts of Northern and

Western Cape, the southern Eastern Cape, as

well as the Drakensberg Mountain Range of

KwaZulu-Natal and Lesotho. Map 14.

The species can be distinguished from others

in the subgenus by its large, rather bloated, straw-

coloured or yellow-green thalli. Riccia gar side i

(no. 6), although closely related, is often larger,

almost white when dry, with many exposed air

chambers; its spores have fewer and larger alveo-

li. Riccia volkii (no. 7) (see note under that

species) is less robust and swollen, with narrowly

winged, smaller spores and its distribution is

restricted to the summer rainfall areas.

Riccia bullosa was originally supposed to also

grow in Portugal (Nees 1838), not Spain as men-

Figure 30. — Riccia bullosa. A, B, thallus: A, male; B, female. C, c/s epidermis and assimilation tissue; D, epidermal

cells and air pores (hatched), overlying air chambers, some partly exposed, others covered (cells stippled); E, air pore

(hatched) and surrounding cells seen from above; F, c/s branch. A, B, S.M. Perold 467\ C-F, Van Rooy 3541 . Scale bars: A,

B, F, 1 mm; C, D, 100 pm; E, 50 pm. Artist: J. Kimpton.

134

HEPATOPHYTA: Ricciaceae

tioned by Duthie & Garside (1937), but as

explained by them, the collection by Link was

subsequently shown to be a species of

Exonnotheca. Stephani (1898) also stated that it

was not a Riccia and later (Stephani 1899)

referred it to Exormotheca welwitschii. Although

Lindenberg (1836) cited both collections, Link’s

from Portugal and Ecklon’s from the Cape, his

illustration (XXIII, fig. 1) is clearly that of R.

bullosa and so are his references to its colour,

groove, air chambers and pores. Muller’s (1947)

selection of Link’s specimen as the lectotype of

Exormotheca bullosa, thus leaving the Riccia

element without a correct name, is therefore not

accepted here; R. bullosa is regarded as the cor-

rect name for this species (Perold 1991b).

Sim’s (1926: 13) note under/?, bullosa, that R.

capensis (the type specimen Brunnthaler s.n.)

(see comment under R. limbata, no. 24) ‘appears

to be a young sterile condition of this’, is inex-

plicable, as they are completely different species,

even belonging in different subgenera! The

Giffen collection, (Herb. Sim, PRE) from

O’Kiep, Namaqualand, which Sim cites, has been

placed under R. schelpei (no. 14), but the Pole

Evans collection from Premier Mine, Gauteng

has not been traced. Judging by its distribution it

is most probably a specimen of R. volkii (no. 7).

Vouchers: Magill PRE-CH4509 (PRE);

Morley 272 (PRE); Oliver 8777 (PRE); S.M.

Perold 467 (PRE); Van Rooy 3541 (PRE).

6. Riccia garsidei Sim, The Bryophyta of

South Africa: 13 (1926); S.W.Arnell: 41 (1963a):

Perold: 62 (1991c). Type: Cape, Stellenbosch

Flats, Garside 2 ( CH1059 ) (PRE, holo.!).

Thalli medium-sized to large or very large,

in gregarious patches or scattered; glaucous to

pale olive or buff, very bloated; when dry, light

smokey grey to white, honeycomb-pitted, sides

not inflexed. Branches simple or once symmet-

rically furcate, mostly shortly divided, moder-

ately to widely divergent, elliptical-oblong to

broadly ovate, 1 0— 1 2(— 1 5) x (4 — )6(— 8) mm,

2. 5-2. 7 mm thick, in section 2-3 times wider

than thick, apex gradually or abruptly tapered,

shortly emarginate; groove deep and narrow

distally, proximally rather flat, thallus margins

obtuse, rounded, sometimes overhanging;

flanks vertical to sloping obliquely; ventral face

rounded or broadly keeled, glaucous to greyish

green. Scales absent.

Dorsal epidermis forming a slightly domed

to flat roof over each air chamber, cells variable

in shape and size, some rectangular, others

hexagonal, 30-85 x 15-35 pm; air pores sur-

rounded by 6 or 7 smaller cells, variable in

shape, 20-25 x ± 12 pm, soon rupturing, com-

pletely exposing air chambers below. Assi-

milation tissue up to 1800 pm thick, air cham-

bers very tall, mostly in one storey, vertical to

obliquely sloping laterally, gradually widening

upward, shape mostly hexagonal when viewed

from above, bounded by unistratose, chloro-

phyllose cell walls; storage tissue occupying

ventral part of thallus, cells angular, closely

packed. Figure 3 1 .

Dioicous. Antheridia sunken in 1 (or 2)

rows, along centre of branches, hyaline necks

protruding individually from quite large hol-

lows. Archegonia serially arranged, thin, pur-

ple necks obscured. Sporangia quite deeply

embedded below midline, mostly crowded

together. Spores (11 8—) 1 20— 1 30(— 135) pm

diam., triangular-globular, polar, golden brown

HEPATOPHYTA: Ricciaceae

135

D

• R. volkii

to tan-brown, semitransparent; wing thin, wavy

up to 10 pm wide, marginal angles perforated,

margin finely crenulate, sometimes with one or

two notches; ornamentation reticulate and sim-

ilar on two spore faces; distal face with 8-10

large, shallow, roundish or angular alveoli

across diam., 12.5-20.0 pm wide, alveolar

walls thin, faintly granular, 2. 5-5.0 pm high,

usually raised at nodes and extending across

wing; proximal face with triradiate mark often

not distinct and interrupted, each of three facets

with ± 18 alveoli, usually more than 15 pm

wide, adjacent ones sometimes confluent, alveo-

lar walls up to 5 pm high, some meeting along

arms of triradiate mark and marginally extend-

ing across wing. Chromosome number : not

known. Plate 14A, B; Perold (1989e: fig.

40.1-6).

This species is endemic to southern Africa

and has been collected in Western Cape on

gravelly or clayey soil. Map 15.

Riccia garsidei is closely related to R. bul-

losa (no. 5), but can be distinguished from it by

its almost white colour when dry, the larger size

Figure 31. — Riccia garsidei. A, B, thallus: A, male; B, female. C, epidermal cells and air pores (hatched) overlying

air chambers, seen from above; D, air pore (hatched) with surrounding cells; E, c/s thallus through air chambers; F, c/s

branch. A-F, Duthie s.n., 15-11-1937. Scale bars: A, B, F, 1 mm; C, E, 100 pm; D, 50 pm. Artist: J. Kimpton.

136

HEPATOPHYTA: RlCClACEAE

Plate 14. — Spores. A, B, Riccia garsidei: A, distal face; B, proximal face. C, D, R. volkii: C, distal face; D, prox-

imal face. E, F, R. rubricollLs: E, distal face; F, proximal face. A, B, Garside 2; C, D, Volk 81/230, E, F, Duthie 5014.

A, B, E, F, x 600; C, D, x 700.

HEPATOPHYTA: RlCCIACEAE

137

of the thalli, the less pronounced and generally

shorter groove and the many exposed, hexago-

nal air chambers. There is a good deal of over-

lap in the size of the spores of the two species,

but in R. garsidei there are generally fewer and

larger alveoli.

Vouchers: Duthie 5002, 5075, 5475 (BOL);

Marais 5464a (BOL); Wilman 663 (BOL).

7. Riccia volkii S.W.Arnell in Mitteil-

ungen der Botanischen Staatssammlung, Miin-

chen 16: 271 (1957); S.W.Arnell: 42 (1963a);

Perold: 63 (1991c). Type: SWA / Namibia,

Otjiwarongo: Kleiner Waterberg, am Rand der

Wannen im roten Sandstein, Boden kalkfrei,

Volk 1029 (M, holo.; PRE, iso.!).

Thalli medium-sized, in crowded, gregarious

patches or scattered, occasionally in rosettes, up

to 20 mm across; pale green to lime-green,

deeply grooved, laterally tumid and swollen,

spongy toward base; when dry, yellowish to

greyish white, sides transversely wrinkled, not

indexed. Branches once to several times fur-

cate, shortly to deeply divided, moderately to

widely divergent, broadly ligulate to lingulate,

up to 9 mm long, segments 2-6 x 2. 5-3. 5 mm,

1.0-1. 2 mm thick, in section 2-3 times wider

than thick, apex obtusely rounded, emarginate;

groove deep and narrow apically, becoming

wider and concave proximally, thallus margins

obtuse, rounded; flanks sloping obliquely, ven-

tral face gently rounded, green. Scales ventral,

vestigial or absent, hyaline. Plate 13B.

Dorsal epidermis areolate, forming a slight-

ly domed to flat roof over each air chamber,

partly chlorophyllose, cells 5- or 6-sided,

47.5-60.0 x 25-40 pm; air pores small, sur-

rounded by 6 or 7(8) radially arranged, smaller

cells, enlarging by rupture of cells as air cham-

bers increase in size. Assimilation tissue ± 650

pm thick, consisting of one storey of almost

vertical air chambers, bounded by unistratose,

chlorophyllose walls of cells; storage tissue

occupying ventral part of thallus, cells angular,

closely packed. Figure 32.

Dioicous. Antheridia in 1 or 2 rows along

groove, hyaline necks emerging from small pits.

Arche gonia embedded, purple necks up to 250

pm long, median. Sporangia bulging dorsally, 2

or 3 linearly arranged toward base, overlying

tissue disintegrating. Spores (88— )90— 100(— 1 1 2)

pm diam., triangular-globular, polar, yellow-

brown to tan, semitransparent; wing thin, nar-

row, 3 pm wide, slightly undulating, pores

occasionally present at marginal angles, margin

finely crenulate; ornamentation reticulate, simi-

lar on 2 spore faces; distal face with 7 or 8 deep,

round or oval alveoli across diam., 10-15 pm

wide, sometimes 2 adjacent alveoli confluent,

with slight constriction where cross wall failed

to develop, alveolar walls rounded, smooth or

finely granular, 3-5 pm high, ± 2.5 pm wide, at

nodes slightly wider, scarcely raised, extending

onto wing; proximal face with triradiate mark

not well defined, faintly granular, each facet

with ± 15 rounded alveoli, up to 10 pm wide,

sometimes confluent or with slight constriction.

Chromosome number: n = 8 (Bornefeld 1984,

1989). Plate 14C, D; Perold (1989e: fig.

42.1-6).

Riccia volkii is a southern African endemic

species and is quite rarely collected in the

savanna and grassland summer rainfall areas of

the region. It is found on damp, gravelly or

sandy soil, overlying quartzite, basalt or red

sandstone rock outcrops in Namibia, Northern

Province, North-West, Gauteng, Mpumalanga,

Free State and southeastern Northern Cape.

Map 15.

The species can be recognized by the small-

ish, hardly robust, lingulate branches of the

lime-green to yellowish thalli. In some respects

it is rather similar to small plants of R. bullosa

(no. 5) and of R. garsidei (no. 6), but the

branches are narrower and more delicate, some-

times forming a rosette. The smaller, narrow-

winged spores with poorly defined, triradiate

mark and rounded alveoli with distinctly wider

walls, scarcely raised at the nodes, also differ

from those of R. bullosa and of R. garsidei (see

notes under those species).

138

HEPATOPHYTA: RlCCIACEAE

Vouchers: S.M. Perold 195, 433 (PRE); J.M.

Perold 38c (PRE); Volk 81/133 , 81/230 (M,

PRE).

8. Riccia rubricollis Garside & A. V.Duthie

ex Perold in Bothalia21: 51 (1991a); S.W.Amell:

35 (1963a); Perold: 64 (1991c). Type: Cape,

Knysna, Belvidere, on turf in shady places, not

far from lagoon, Sept./Oct. 1929, Duthie 5014

(BOL, lecto.!; PRE, isolecto.!).

Thalli medium-sized to large, in gregarious

patches, sometimes with branches overlying, or

scattered, not in rosettes; yellowish green, occa-

sionally with some purple blotches; when dry,

straw-coloured to light brown, margins not

inflexed, somewhat raised, dorsally pitted in

older parts. Branches rarely simple, mostly

once or twice symmetrically or asymmetrically

furcate, moderately to widely divergent, oblong

or somewhat linear, up to 12 mm long, seg-

ments 2. 5-6.0 x 2. 8-3.0 mm, 0.7-1. 0 mm thick

medianly, in section 2-4 times wider than thick,

apex tapered, ventrally keeled; groove only dis-

tally deep, soon shallow and wide, thallus mar-

gins subacute, rather irregularly undulating,

winged; flanks sloping obliquely to very

obliquely, yellowish; ventral face rounded or

keeled medianly. Scales toward apex only, ven-

tral, small, hyaline.

Dorsal epidermis forming slightly domed to

flat roof over large air chambers, cells oblong-

hexagonal or 5-sided, 62-80 x 50 pm; air pores

apically small, surrounded by slightly curved,

narrow, elongated cells, soon disintegrating and

air pores rapidly enlarged, leaving air chambers

exposed. Assimilation tissue 400-750 pm thick,

air chambers 5- or 6-sided, elongated, mostly in

one storey, generally 12 across width of thallus,

sloping laterally and widening toward top,

bounded by unistratose, chlorophyllose cell

Figure 32.— Riccia volkii. A, thallus; B, epidermal cells and air pores (hatched), overlying air chambers, seen from

above; C, air pore (hatched) and surrounding cells from above; D, c/s epidermis and assimilation tissue; E, h/s air chambers

(stippled); F, c/s branch. A, S.M. Perold 433\ B-F, S.M. Perold 2472. S cale bars: A, F, 1 mm; B, D, E, 100 pm; C, 50 pm.

Artist: J. Kiinpton.

HEPATOPHYTA: RlCCIACEAE

139

Figure 33. — Riccia rubricollis A, B, thallus: A, male;

B, female. C, epidermal cells and air pores (hatched), over-

lying air chambers seen from above; D, air pore (hatched)

with surrounding cells; E, c/s showing air chambers; F, c/s

female branch. A-F, Duthie 5014. Scale bars; A, B, F, 1

mm; C, E, 100 pm; D, 50 pm. Artist: J. Kimpton.

walls; storage tissue occupying ventral part of

thallus, cells empty, angular. Figure 33.

Stolons confined to the thickened, perennat-

ing tips of some branches.

Dioicous. Antheridia sunken in a row along

midline of branches, when mature bulging dor-

sally, with conspicuous, mostly dark purple

necks, up to 300 pm long. Arche gonia 3 or 4

serially arranged toward base, necks purple,

thin, hidden. Sporangia deeply imbedded, not

bulging dorsally or protruding ventrally, but

eventually opening to upper surface. Spores

92-100(-105) pm diam., triangular-globular,

polar, reddish brown to deep russet-brown, semi-

transparent to opaque; wing 5 pm wide, at mar-

ginal angles wider, perforated and often else-

where too, margin finely crenulate, slightly undu-

lating; ornamentation completely or incompletely

reticulate, rather different on 2 spore faces; dis-

tal face with 5 or 6 alveoli across diam., central

ones larger, 20-25 pm wide, smaller toward

margin, ± 10 pm wide, walls 4 pm thick and 6

pm deep, shallower laterally, not raised at nodes;

proximal face with triradiate mark prominent,

widening toward marginal angles at juncture

with wing, alveoli up to 12 pm wide, mostly

incomplete, walls slightly raised at nodes.

Chromosome number : not known, as living

material not available. Plate 14E, F.

Riccia rubricollis is only known from

Knysna in the southeastern Western Cape,

where it was collected on a few occasions by

Duthie. It has so far not been found elsewhere

in southern Africa. It grows in damp, shady

places, on dark grey, somewhat gravelly turf, in

association with R. purpurascens (no. 10),

Fossombronia sp. and Pleuridium sp. Map 16.

The species is easily recognized by the sin-

gle conspicuous row of deep purple antheridial

necks along the midline of the ± linear, apically

tapering branches of the male plants. The spe-

cific epithet, R. rubraosteolata in Duthie’s

handwriting, appears on one of her collections,

140

HEPATOPHYTA: RlCClACEAE

which she kept in cultivation at Stellenbosch.

Unfortunately, she and Garside did not publish

a description of this rare, endemic species. Later

on, S.W. Arnell (1963a) described it under the

name R. rubricollis, but without providing a

Latin description or citing a type specimen.

This has now been done (Perold 1991a), after

Duthie’s specimens, following an extended

search, were relocated at BOL. Although more

robust and fleshy, R. rubricollis is clearly relat-

ed to R. purpurascens (no. 10), because of its

somewhat linear habit, but it is not classified

together with R. purpurascens and R. stricta

(no. 9) in section Ricciella, as the sporangia do

not conspicuously bulge ventrally. Na-Thalang

(1980) regards the Australian species, R. colla-

ta, as having the closest affinity to R. rubricol-

lis, although the latter plant is larger and the

alveoli on the distal face of the spores are wider.

Map 16. — Q Riccia rubricollis

0 R. purpurascens

Voucher: Duthie 5406 (BOL).

A2. Section Ricciella (A. Braun, pro gen.) Bisch., Nova acta Academiae Caesareae Leopoldino-

Carolinae Germanicae Naturae Curiosorum 17: 1068 (1835). Lectotype: R. fluitans L. fide Grolle:

248 (1976).

Thalli smallish to rather large; terricolous or aquatic. Branches linear, quite firm or lax, 10-15

mm long, sparsely furcate. Scales ventral, mostly only toward apex, very small to small, single or

split, without central appendage.

Dorsal epidermis chlorophyllose; air pores small, surrounded by smaller companion cells, not

becoming lacunose. Assimilation tissue with polyhedral air chambers enclosed by unistratose walls.

Sporangia bulging and opening ventrally; vertical or oblique. Spores smallish, alveolar walls

thick or partly thick.

9. Riccia stricta (Lindenb.) Perold in

Bothalia 20: 197 (1990f); Perold: 65 (1991c).

Type: Cape, Philipstown, ad arborum truncos

(!?), Ecklon s.n. (BM, lecto.!).

R. fluitans L. var. 5 stricta Lindenb : 85 (1836).

R. fluitans L. var. 8 stricta Nees: 440 ( 1 838).

R. fluitans L. var. ?e stricta Gottsche et al.: 610 (1844-

1847). Type: Cape, Philipstown, Ecklon s.n. (BM!).

Invalidly published or unpublished synonyms

R. tenerrima Steph. leones ined. Type: Natal, Dist.

Alexandra, Sta. Dumisa, leg. Rudatis (M).

R. stricta A.V.Duthie ined. fide S.W. Arnell: 37 (1963a).

? Ricciella stricta (Gottsche et al.) Trevis.: 62 (1877).

Thalli small to medium-sized, in dense, tan-

gled masses; bright green, often with purple

streaks along margins; when dry, flattened to

almost unchanged. Branches repeatedly symme-

trically or asymmetrically furcate, moderately

to widely divergent, linear or strap-shaped, 15-

20 mm long, segments 5 mm or more long,

(0.3-)0.5-0.8(-1.2) mm wide, 0.25-0.35(-0.5)

mm thick, in section 1— 3(— 4) times wider than

thick, apex slightly narrowed, somewhat taper-

HEPATOPHYTA: Ricciaceae

141

ing, occasionally bulbous; groove only visible

distally in living plants, thallus margins round-

ed, obtuse to subacute; flanks vertical to sloping

obliquely to almost flat; ventral face gently

rounded to flat, green. Scales under apex and

spaced at short or rather longer intervals along

ventral face of terminal segments, small, up to

250-500 x 150-400 pm, apically single, soon

splitting into two halves, obtusely triangular,

concave, hyaline, occasionally somewhat pur-

ple. Plate 13C.

Dorsal epidermis not distinctly areolate,

forming a rather smooth cover over elongated

air chambers, cells long-hexagonal, 42-65 x

25-50 pm, smaller and isodiametric at margins,

± 25 x 25 pm; air pores small, surrounded by

ring of 5 or 6 smaller companion cells, partly

overlying slightly thicker-walled epidermal

cells. Assimilation tissue 100-500 pm thick, air

chambers in 1 or 2 storeys medianly, uniseriate

laterally, bounded by unistratose chlorophyl-

lose cell walls; storage tissue occupying ventral

part of thallus, cells rounded. Figure 34.

Perennation by apical bulbils or by ventral

stolons.

Monoicous. Antheridia near apex and more

proximally, at intervals medianly along branch-

es, necks hyaline, conspicuous, 150-200 pm

long, basally surrounded by low, hyaline, coni-

cal cells. Archegonia median, up to 3 per seg-

ment, serially arranged, sometimes interspersed

between antheridia, obliquely orientated, necks

purple, 100-250 pm long, sloping at an angle

toward, and opening into shallow, apically

directed furrow, the ‘blind’ end fringed with

erect, hyaline, conical cells. Sporangia at gen-

erally wider and always thicker sites along thal-

lus, oblique and protruding conspicuously ven-

trally, covering tissue abundantly supplied with

Figure 34. — Riccia stricta. A, thallus; B, ventral stolon; C, air pore (hatched) with thin-walled surrounding cells and

thicker-walled epidermal cells, part of air chamber stippled; D, 1/s sporangium; E, c/s narrow branch from drier habitat; F,

c/s thin, wide branch from wet habitat; G, ventral face with scales, apically single, others split into two; H, single scale; I,

antheridial neck with basal collar of conical cells. A, Van Rooy 3539 ; B, Van Zinderen-Bakker 7472\ C, S.M. Perold 861 ; D,

S.M. Perold 365\ E, G, S.M. Perold 354\ F, Magill 6592\ H, T.R. Sim PRE-CHI 11 9, I, S.M. Perold 842. Scale bars: A, B, 1

mm; C, I, 50 pm; D, F, G, 200 pm; E, H, 100 pm. Artist: J. Kimpton.

142

HEPATOPHYTA: RlCClACEAE

Plate 15. — Spores. A. B, Riccia stricta: A, distal face; B, proximal face. C, D, R. purpurascens: C, distal face;

D, proximal face. E, F, R. curtisii: spore tetrads. A, R.J. Word 5354\ B, Wells 57\ C, S.M. Perold 5ft7\ D, Garside

7; E, F, S.M. Perold 2059. A, x 1000; B, D, x 800; C, x 740; E, F, x 600.

HEPATOPHYTA: RICCIACEAE

143

rhizoids. Spores (50-)62-70(-75) pm diam.,

triangular-globular, polar, light brown, semi-

transparent; wing thick, 7.5 pm wide, wider at

perforated or notched marginal angles, with a

row of fine granules along edge, margin crenu-

late; ornamentation reticulate, different on 2

spore faces; distal face highly convex, with

(4— )5 or 6 large, deep alveoli across diam. of

spore, 17-20 pm wide, in centre a pillar or boss,

from which several low ridges radiate outward,

sometimes forming a network, alveolar walls

rounded, 3-4 pm wide and up to 7.5 pm high,

sometimes sparsely granulate; proximal face

with triradiate mark very prominent, up to 5 pm

high, as wide (or wider) toward marginal angles

at join with wing, each facet with 6-10 alveoli,

some incomplete, often subdivided by faint

radiating ridges, walls thin, raised at nodes.

Chromosome number: n = 8 (Bornefeld 1989).

Plate 15A, B; Perold (1989e: fig. 34.1-6).

Riccia stricta is known from Angola, Burundi,

Cameroon, Ethiopia, Ghana, Ivory Coast, Kenya,

Malawi, Mozambique, Niger, Nigeria, Rwanda,

Sudan, Tanzania, Togo, Uganda, Zaire, Zambia,

Zimbabwe and southern Africa (Perold 1995b).

In the FSA area it is widely distributed in the sum-

mer rainfall areas especially, and is one of the

most commonly collected Riccia species in the

region. It is either terrestrial, growing on mud or

damp soil, or aquatic, when it floats on, or is sub-

merged in fresh or stagnant water. It is recorded

from Namibia, Botswana, Northern Province,

North-West, Gauteng, Mpumalanga, Free State,

KwaZulu-Natal, Lesotho, Northern, Western and

Eastern Cape. Map 17.

Species in the R. fluitans complex are diffi-

cult to distinguish, as the gametophytes are

highly sensitive to different environmental con-

ditions and the habitat can vary from terrestrial

to aquatic. Nevertheless, R. stricta can general-

ly be recognized by its mostly smooth dorsal

surface, through which the large air chambers

are faintly to fairly clearly visible, by small ven-

tral scales and by smallish spores with large,

deep- walled alveoli containing a central boss on

the distal face and, on the proximal face, a

prominent triradiate mark.

Map 17. — • Riccia stricta

□ R. curtisii

■ R. perssonii

R. fluitans L. sensu stricto is thought not to

occur naturally in southern Africa (Perold

1990f) and very rarely produces spores wherev-

er it grows.

Vouchers: Glen 1832 (PRE); Magill 5039

(PRE); Mauve & Venter 5077 (PRE); S.M. Perold

2455 (PRE); Van Zinderen-Bakker 7472 (BOL).

10. Riccia purpurascens Lehm. in Linnaea

4: 371 (1829); Lindenb.: 451 (1836); Gottsche

et al.: 611 (1844-1847); Steph.: 363 (1898);

Sim: 15 (1926); S.W.Arnell: 36 (1963a);

Perold: 203 (1990f); Perold: 66 (1991c). Type:

Cape, crescit humi in sylvula quercina ad latus

boreale et ad radicem montis Tafelberg in

Promont. Bonae Spei, Ecklon s.n. (S, holo. ! ; G,

iso.!).

Ricciella purpurascens (Lehm.) Lehm.: 23 (1832);

Trevis.: 62 (1877).

Thalli medium-sized to fairly large, in thin,

creeping strands or ribbons, frequently overlap-

ping and becoming quite densely massed; light

green, occasionally purple along margins and

over gametangia; when dry, yellowish green,

flaccid and rather flat. Branches repeatedly and

irregularly furcate, narrowly to moderately

divergent, linear, 9-17 mm long, segments 1-5

144

HEPATOPHYTA: RlCClACEAE

x 1. 5-2.0 mm, 0.4-0.6 mm thick medianly over

keeled ventral part, wings thinner, in section

3-5(-7) times wider than thick, apex narrowed,

shortly emarginate; groove distinct distally,

soon becoming wide and shallow, thallus mar-

gins subacute, rather irregularly undulating,

winged or attenuate; flanks sloping obliquely to

almost flat, green; ventral face flat to narrowly

keeled medianly. Scales toward apex only, ven-

tral, difficult to detect, spaced and split into 2

halves, up to 3 pairs, hyaline. Plate 13D.

Dorsal epidermis areolate, forming flat

cover over large air chambers, cells oblong-

hexagonal or 5-sided, 87.5-110.0 x 60-75 pm,

at apical margin rectangular, smaller, ± 45 x 30

pm; air pores small, surrounded by 4 or 5 radi-

ally arranged, thin-walled cells, partly overly-

ing slightly thicker-walled epidermal cells.

Assimilation tissue 300-400 pm thick, occupy-

ing most of thickness of thallus, air chambers

polyhedral, in 2 storeys medianly, uniseriate lat-

erally, bounded by unistratose chlorophyllose

walls; storage tissue confined to central keeled

part, mostly only 1-4 layers of angular cells.

Figure 35.

Perennation by ventral stolons.

Dioicous. Antheridia serially arranged in

groups of 2 or 3, with sterile areas in between,

along middle of thallus, bulging above and

below, necks up to 200 pm long, bases encircled

by hyaline, conical cells. Archegonia single or

in pairs, sometimes adjacent, median, vertically

orientated, necks short, brownish purple with

hyaline tips, opening into a depression, base

surrounded by conical cells. Sporangia causing

thallus to widen laterally and to bulge ventrally.

Spores (65— )70— 80(— 88) pm diam., triangular-

globular, polar, yellow to bright brown, semi-

transparent; wing thick, up to 7.5 pm wide, at

marginal angles 2 small pores, one on either

side of each arm of triradiate mark, margin fine-

Figure 35. — Riccia purpurascens. A, thallus; B, ventral face with stolons and sporangium; C, dorsal face with air

chambers and epidermal cells partly drawn in; D, air pore (hatched), with thin-walled surrounding cells and thicker-walled

epidermal cells, part of air chamber stippled; E, c/s branch at sporangium; F, c/s sterile part of branch. A, B, F, Morley 291 ;

C, S.M Perold 1941 ; D, E, S.M. Perold 1170. Scale bars: A-B, C, 1 mm; D, 50 pm; E, F, 200 pm. Artist: J. Kimpton.

HEPATOPHYTA: RlCCIACEAE

145

ly crenulate; ornamentation incompletely retic-

ulate, different on 2 spore faces; distal face with

4-6 large, angular, mostly incomplete alveoli

across diam., ± 20 pm wide, usually subdivided

into smaller alveoli by secondary ridges or a

central pillar, toward margin often reduced to

short ridges only, walls 5 pm high, densely

fringed with granules, slightly raised at nodes;

proximal face with triradiate mark prominent,

2.5 pm wide, becoming wider toward marginal

angles at juncture with wing, row of superim-

posed papillae running along arms, on each of 3

facets rarely any complete alveoli, mostly short

broken walls, straight or curved, edged with

tall, uneven spines, warty papillae or low gran-

ules. Chromosome number, n = 8 (Bornefeld

1989). Plate 15C, D; Perold (1989e: fig.

35.1-6).

Endemic to southern Africa, R. purpurascens

has been collected in the western part of Northern

Cape and Western Cape, which are winter rainfall

areas (Map 16). It grows on damp, sandy soil or

on mud. It is not nearly as widespread as R. stric-

ta (no. 9), which occurs mostly in summer rainfall

regions; only in the southern parts of Western

Cape do their distribution areas overlap. Arnell

(1963a) also reported R. purpurascens from

Victoria Falls, Zimbabwe, but this specimen, T.R.

Sim 9066 , had been misidentified and actually is

R. stricta , as is the specimen Eyles 1237 , cited by

Best (1990) from Zimbabwe.

Riccia purpurascens can be recognized by

its long, thin, rather lax, linear branches, fre-

quently tinged with purple and keeled ventral

face, from which stolons arise. The ventrally

protruding sporangia are vertically orientated

and not oblique as in R. stricta, the archegonial

necks are shorter, the spores are generally

slightly larger than those of R. stricta (no. 9),

and the ornamentation is different.

Vouchers: S.W Arnell 332 (BOL); McLaugh-

lin PRE-CH4197; S.M. Perold 634a , 1770

(PRE).

B. Subgenus Thallocarpus

Thallocarpus (Lindb.) Jovet-Ast, Revue bryologique et lichenologique 41: 452 (1976).

R.M.Schust.: 413 (1985); Perold: 67 (1991c); Jovet-Ast: 220 (1993). Type: R. curtisii (James ex

Austin) Austin.

Cryptocarpus sensu Austin: 231 (1870) not of Kunth: 187 (1817). Thallocarpus Lindb.: 377 (1874). Angiocarpus Trevis.:

444(1877).

Riccia section Thallocarpus Austin: 305 (1879).

Plants heterothallic; terricolous. Scales absent.

Dorsal epidermis chlorophyllose, unistratose, lacunose. Assimilation tissue with polyhedral air

chambers.

Sporangia immersed. Spores remaining adherent in tetrads, ornamentation with slender spinules

or stout spines.

11. Riccia curtisii (James ex Austin) Austin

in Bulletin of the Torrey Botanical Club 6: 305

(1879); Steph.: 369 (1898); Haynes: 284 (1920);

A.V.Duthie & Garside: 122 (1937); Frye &

L.Clark: 32 (1937); Hassel de Menendez: 218

(1963); S.W. Arnell: 36 (1963a); Jovet-Ast: 452

(1976); Vianna: 76 (1981); Perold: 67 (1991c);

R.M.Schust.: 509 (1992b); Jovet-Ast: 221

(1993). Type: North Carolina, Society Hill, leg.

Curtis s.n., 1853; on moist ground, South

Carolina, Ravenel, leg. Curtis s.n., 1849 (Hb.

Sulk).

146

HEPATOPHYTA: Ricciaceae

Cryptocarpus curtisii Austin: 231 (‘Dec. 1869’, 1870)

nom. illeg. Angiocarpus curtisii (Austin) Trevis.: 444

(1877). Thallocarpus curtisii (Austin) Lindb.: 377 (1874);

Austin: 21 (1875); McAllister: 117 (1916).

For further synonymy see Jovet-Ast (1993).

Riccia spongosa S.W.Amell: 310 (1952); S.W.Amell: 38

(1963a). Type: Cape, George, Wilderness, forest path '/2

mile east of the hotel, S.W Arnell 1393 (BOL, holo.!).

Plants heterothallic, male thalli very small,

frequently partly overgrown by female thalli;

yellowish to reddish brown in some areas, often

with some purple colouration; female thalli

smallish to medium-sized, scattered or crowd-

ed, in complete or incomplete rosettes, up to 10

mm, rarely to 20 mm across; light green to yel-

lowish green, dorsally intact toward apex, soon

becoming pitted and spongy; when dry, margins

not inflexed, dull green, lacunose. Branches in

female plants once to several times pseudodi-

chotomously furcate, shortly to deeply divided,

almost overlapping to narrowly divergent,

oblong or quite variable, 2-8 x 2-4 mm, up to 1

mm thick, in section 2-4 or more times wider

than thick, apex truncate to rounded, emar-

ginate; groove indistinct, thallus margins

obtuse, rounded; flanks sloping obliquely to

nearly flat; ventral face slightly rounded to flat,

green. Scales absent.

Dorsal epidermis slightly domed over each

air chamber, soon disintegrating, cells 100-150

x 75-80 pm, but quite variable in size and

shape; air pores surrounded by rather smaller,

unmodified and regularly arranged cells, at

apex small and inconspicuous, rapidly enlarg-

ing, becoming almost as wide as air chambers,

irregularly polygonal to oblong. Assimilation

tissue up to 750 pm thick, air chambers polyhe-

dral, sloping, much enlarged proximally,

enclosed by unistratose, chlorophyllose cell

walls; storage tissue restricted to 3-5 ventral

cell rows. Figure 36.

Figure 36. — Riccia curtisii. A, female thallus with small male thallus protruding from underneath on left side; B, epi-

dermal cells and air pores (hatched) from above; C, h/s assimilation tissue, air chambers stippled; D, c/s epidermis and

assimilation tissue; E, c/s branch A, S.M. Perold 641\ B-E, S.M. Perold 2395a. Scale bars: A, E, 1 mm; B-D, 100 pm.

Artist: J. Kimpton.

HEPATOPHYTA: RICCI ACEAE

147

Dioicous. Antheridia with numerous and

conspicuous necks in one or two rows along

middle of small male plants, hyaline, up to 200

pm long, basally surrounded by conical cells.

Arche gonia scattered, necks ± 200 pm long,

base purple. Sporangia several, crowded to-

gether. Spores in tetrads, ( 100—) 1 05—1 1 5(— 125)

pm diam., yellow-brown to tan-brown, semi-

transparent; wingless; usually only three spores

of tetrad visible, occasionally all 4, joined by

narrow band or ridge; ornamentation reticulate,

variously developed, with small, deep, round

alveoli or fovea, 2.5-3. 5 pm wide, extending to

connecting band, alveolar walls low and thin,

raised at nodes into stout, conspicuous, truncate

processes, up to 5 pm long in centre of convex

face, lower toward sides, tips of processes

crowned with numerous granules. Chromosome

number: n = 8 (Siler 1934; Jovet-Ast 1975;

Bornefeld 1989). Plate 15E, F; Perold (1989e:

fig. 45.1-6).

The species is quite widely distributed and is

known from North, Central and South America,

India, North Africa (Chad) and southern Africa.

In the FSA area, R. curtisii is fairly rare; it

has been collected at seepages on soil derived

from granitic rock in the shrublands of western

Northern Cape, on cultivated soil in a wheat-

field and on garden paths in the southern part of

Western Cape. Map 17.

Riccia curtisii can be distinguished from

other Riccia species by the generally very

loosely reticulate composition of its thalli, and

the spores which adhere permanently in tetrahe-

dral tetrads.

Riccia spongosa is regarded as a synonym of

R. curtisii (Perold 1991c); its spore tetrads

appear to be rather young and therefore, mis-

leading in their so-called differences.

Duthie & Garside (1939) described a closely

related species, R. compacta, which they distin-

guished from R. curtisii by the firmer composi-

tion of its thalli and by the more compact nature

of its air chambers, by well-marked tuberculate

rhizoids and by characteristic spore markings.

They dismissed the possibility that R. compacta

could be a growth form of R. curtisii. Very few

collections of R. compacta were available for

study. Herbarium specimens proved to be un-

suitable for the critical examination necessary

to verify the differences between the thalli of R.

curtisii and R. compacta, and culture experi-

ments with fresh material were unsuccessful.

Whether to accept or reject R. compacta as a

distinct species, remains unresolved.

Vouchers: S.W Arnell 12 (BOL); Duthie

5018, 5486 (BOL); S.M. Perold 474, 479 (PRE).

12. Riccia perssonii S. A. Kahn in Svensk

botanisk tidskrift 49: 433 (1955); S.W.Arnell:

37 (1963a); Jovet-Ast: 149 (1967); Jovet-Ast:

449 (1976); Perold: 68 (1991c). Type: Bang-

ladesh (= East Pakistan), Dacca, growing on

shaded soft mud along the edge of a pond, Kahn

1 (Dacca Univ.).

Plants heterothallic, male thalli very small,

once pseudodichotomously furcate; female

thalli small to medium-sized, scattered, report-

ed to form rosettes up to 11 mm across; light

green, dorsally spongy. Branches once or twice,

sometimes up to 3 times pseudodichotomously

furcate, shortly to deeply divided, moderately

divergent, oblong, 2-4 x 0.5-1. 3 mm, ± 0.3 mm

thick, in section 2-4 times wider than thick,

apex rounded to acute; groove not observed,

thallus margins acute; flanks sloping obliquely

to almost Hat; ventral face slightly rounded to

flat, green. Scales absent.

Dorsal epidermis pitted by numerous small

to large air pores, irregularly shaped. Assi-

milation tissue occupying most of thickness of

thallus, air chambers polyhedral, bounded by

chlorophyllose, unistratose cell walls; storage

tissue consisting of only a few layers of cells.

Figure 37.

Dioicous. Antheridia with hyaline necks,

125 pm long, in 1 or 2 rows along middle of

branches, basally surrounded by conical cells. Ar-

chegonia with purple necks, in rows. Sporangia

148

HEPATOPHYTA: RlCClACEAE

Plate 16. — Spores. A, B, Riccia perssonii, spore tetrads. C, D, R. tomentosa, spore tetrads. E, F, R. schelpei:

E, distal face; F, proximal face. A, B, Volk 2059 ; C, D, S.M. Perold I495\ E, F, S.M. Perold 1426a. A-D, x 600; E,

F, x 700.

HEPATOPHYTA: RlCCIACEAE

149

single, at base of branches or several crowded

together in centre of thalli. Spores in tetrads,

(90— )95— 1 02(— 1 10) |im diam., tan-brown, semi-

transparent; wingless; all 4 spores of tetrad

lying in one plane and usually visible at one

time, in rhomboidal to square isobilateral

tetrads, joined together by broad bands, up to

17.5 pm wide, mostly smooth or with only a

few scattered granules; ornamentation with

occasional small, round alveoli on convex face,

obscured by tall, crowded, spinous processes,

10-15 pm high, broader at base and tapering to

narrow tip, straight or bent, sometimes truncate

and crowned with granules. Chromosome num-

ber: n = 8 (Jovet-Ast 1976). Plate 16A, B;

Perold (1989e: fig. 44.1-6).

Except for Bangladesh, R. perssonii is also

known from the north-central and northwestern

African countries, Chad and Mali respectively

(Jovet-Ast 1967, 1976), from Madagascar

(Perold 1995b), and from southern Africa.

In the FSA area R. perssonii has only been

collected twice in the far northern part of

Namibia, on lime-free, damp, black, clayey soil.

Map 17. It is possible that the Stephens specimen

from neighbouring Botswana (Chobe), reported

by Duthie & Garside (1937) under R. curtisii (no.

11), could be placed here, as the distribution of R.

curtisii in southern Africa appears to be strictly

confined to the winter rainfall areas of the Cape;

besides, they were not familiar with it, as R.

perssonii had not yet been described at that time.

Unfortunately this specimen has not been traced.

B

Figure 37. — Riccia perssonii. A, female thallus; B, c/s

branch. A, B, Volk 2059. Scale bars: A, B, 1 mm.

The collections at PRE are rather fragmen-

tary and cell dimensions could not be measured,

as the fragile material failed to swell out satis-

factorily on wetting. Riccia perssonii is distin-

guished from R. curtisii mainly by spore char-

acters, viz. isobilateral tetrads with prominently

large spines on the convex faces.

Vouchers: Smook 7612 p.p. (PRE); Volk 2059

(M, PRE).

C. Subgenus Pannosae

Pannosae ( Perold ) Perold , subgen. nov., Taxonomic revision of the Ricciaceae Rchb.

(Marchantiales: Hepaticae) in southern Africa: 69 (1991c). Type: R. tomentosa O.H.Volk & Perold.

Pannosae Perold, pro sectione in Volk & Perold: 28 (1990).

Chaetoriccia R.M. Schust., pro sectione in R.M. Schust.: 271 (1992a).

Plants large, not heterothallic, terricolous. Scales large, triangular, apices filamentous.

Dorsal epidermis with numerous, long, multicellular hair-like outgrowths, slightly raised at

base; air pores spaced. Assimilation tissue with large, elongated, polygonal air chambers.

150

HEPATOPHYTA: Ricciaceae

Sporangia immersed. Spores in globular or tetrahedral tetrads, ornamentation papillose.

Section Pannosae Perold (Volk & Perold 1990), created to accommodate R. tomentosa on

account of its tetrad spores, and placed under subgenus Thallocarpus, was elevated to the rank of

subgenus Pannosae (Perold) Perold (1991c). There are several important differences which sepa-

rate R. tomentosa from the two species in subgenus Thallocarpus, R. curtisii and R. perssonii: the

dense hair-like cellular outgrowths from the dorsal epidermis, which does not become lacunose, the

large triangular scales, apically filamentous, the absence of heterothally and the sandy, xeric habi-

tat. These differences are regarded as radical enough to support such a decision.

13. Riccia tomentosa O.H. Volk & Perold

in Bothalia 20: 25 (1990); Perold: 69 (1991c).

Type: Cape, Pedroskloof, on road to Rooifontein,

2 km beyond Willem Stone Bridge, sandy soil,

S.M. Perold 1495 (PRE, holo.).

Thalli large to very large, in crowded, gre-

garious patches or scattered; dorsally shaggy-

haired, silvery to dusty grey; when dry, deeply

concave toward centre, margins erect or scarce-

ly inflexed, hairs matted, whitish. Branches

simple or symmetrically to asymmetrically fur-

cate, moderately divergent, oblong to ovate-

oblong, up to 18 x 2 — 4(— 5) mm, narrower prox-

imally, 3-4 mm thick, in section as wide as

thick, apex slightly narrowed, shortly emar-

ginate; groove short and wide, middle part con-

cave, thallus margins raised, obtuse, shortly

winged; flanks sloping steeply, green, toward

lower, ventral parts occasionally reddish purple;

ventral face rounded to flat, light green. Scales

large, triangular ± 1500 pm long, base up to

1200 pm wide, imbricate, hyaline, apically

divided into loose filamentous strands, one cell

wide, up to 1000 pm long. Plate 13E.

Dorsal epidermis over air chambers slightly

domed, with outgrowths of free-standing,

straight or bent, hair-like cell pillars, up to 2700

pm long, composed of (2— )5— 1 4 cells, 50-270 x

50-100 pm, tapering upwards from broad base,

thin-walled, hyaline; air pores spaced, sur-

rounded by 5 or 6(7) radially arranged, wedge-

shaped cells. Assimilation tissue ± 500 pm

thick, air chambers sloping, elongated, polyhe-

dral, bounded by unistratose, chlorophyllose

walls of isodiametric cells; storage tissue in

ventral part of thallus, cells angular, with small

spaces between. Figure 38.

Dioicous. Antheridia and archegonia not

observed, as obscured by dense dorsal hairs.

Sporangia bulging dorsally, overlying tissue

tinged with mauve. Spores in tetrads, 115-145

pm diam., pale yellow to rust-brown, semitrans-

parent; wingless; in globular to tetrahedral

tetrads, sometimes only 3 spores of tetrad visible,

but occasionally part of 4th spore also seen,

joined together by narrow bands, almost totally

obscured by papillae; ornamentation densely

papillate to verruculose, with papillae 3-5 pm

wide and equally high, obtuse or truncate, arising

from nodes of scarcely visible, to obvious reticu-

lum. Chromosome number: n = 8 (Bomefeld

1989). Plate 16C, D; Perold (1989e: fig. 48.1-6).

The species is rarely collected and is endem-

ic to the arid shrublands of Namaqualand,

Northern Cape, where it is found on reddish

brown, coarse, sandy soil, overlying clay. Map

18. Riccia tomentosa differs from other Riccia

species by the unique, long, vertical, hair-like,

cellular outgrowths from many of the epidermal

cells, often basally slightly raised in support, by

the well-spaced stomata, as well as by the papil-

lose to verruculose spores in permanent tetrads.

It shares the unusual character of large triangu-

lar scales, apically split into filamentous cellu-

lar strands with R. hirsuta (no. 51) — see note

under that species.

On account of its tetrad spores, which it

shares with R. curtisii (no. 11) and R. perssonii

(no. 12), R. tomentosa, section Pannosae Perold

(Volk & Perold 1990), was initially also

referred to subgenus Thallocarpus, but the

marked differences in the morphology of R.

tomentosa indicate that it is better placed in a

subgenus of its own. Section Pannosae has

HEPATOPHYTA: Ricci aceae

151

Map 18. — ■ Riccia tomentosa

□ R. schelpei

• R. trichocarpa

therefore been elevated in rank to subgenus

Pannosae (Perold) Perold.

Vouchers: S.M. Perold 1556 (PRE); Perold

& Reid 1462 (PRE); Perold & M.J.A.W. Crosby

2157 (PRE); Schelpe 7784 (BOL).

Figure 38. — Riccia tomentosa. A, thallus; B, c/s dorsal hair pillars and below, top of assimilation tissue; C, cells sup-

porting base of large hair on right and small hair on left. D, as seen from below: h/s near dorsal surface with air chambers

(stippled) exposed on left, and air pores (hatched) and epidermis on right. E, c/s branch; F, scale. A, S.M. Perold 1495', B-D,

F, S.M. Perold & Crosby 2157', E, S.M. Perold 1556. Scale bars: A, E, 1 mm; B-D, F, 100 pm. Artist: J. Kimpton.

152

HEPATOPHYTA: RlCCIACEAE

D. Subgenus Chartacea

Chartacea Perold, in Volk & Perold in Bothalia 16: 29 (1986b). Type: R. schelpei Volk & Perold.

Thalli quite large, deeply grooved, acutely winged; terricolous. Scales extending to margins of

thallus.

Dorsal epidermis with thick-walled hyaline cells, on drying becoming parchment-like; air pores

surrounded by ring of smaller, superimposed thin-walled cells. Assimilation tissue with large, poly-

hedral air chambers.

Sporangia immersed. Spores reticulate-foveolate, alveolar walls granulate or almost smooth.

14. Riccia schelpei O.H.Volk & Perold in

Bothalia 16: 29 (1986b); Perold: 70 (1991c).

Type: Cape, Goegap Nature Res., Carolusberg

(W), seepage area, Schelpe 7775 (BOL, holo.!;

PRE, iso.!).

Thalli medium-sized to large, in gregarious

patches or scattered; green, somewhat shiny to

greasy, dorsally faintly areolate; when dry, api-

cal sides tightly inflexed and opposing, some-

times clasped together, otherwise wings expand-

ed, irregularly undulate, yellow and parchment-

like. Branches simple or symmetrically or asym-

metrically once or twice furcate, moderately to

widely divergent, oblong-ligulate, up to 12 x

3-6 mm, 1 .5-2.0 mm thick, in section 2-3 times

wider than thick, apex rounded, emarginate,

keeled below; groove deep distally, sides convex

and steeply sloping, more proximally shallow

and wide, thallus margins winged, acute, attenu-

ate; flanks sloping steeply and abruptly into

undulating wing; ventral face slightly convex,

greenish. Scales large, up to 1500 x 300-500

pm, projecting slightly above thallus margins,

imbricate, hyaline with some scattered purple

cells at base, margin entire. Plate 13F.

Dorsal epidermis unistratose, cells variously

shaped, polygonal, 35-70 x 30-50 pm, hyaline,

thick-walled; air pores surrounded by superim-

posed ring of 5-8 smaller, roundish, fragile

cells. Assimilation tissue 750-1300 pm thick,

with wide polyhedral, sloping air chambers

bounded by unistratose, chlorophyllose walls;

storage tissue occupying ventral part of thallus,

cells rounded. Figure 39.

Monoicous. Antheridia with short, hyaline

necks. Archegonia with hyaline tips of necks

above purple-brown bases, emerging from deep,

cup-like depressions at intervals along dorsal

groove, necks at their bases surrounded by

numerous fragile, blunt cells. Sporangia crowd-

ed together or scattered along groove, bulging

dorsally, enclosed in red-brown sac, later disin-

tegrating. Spores 90-115 pm diam., triangular-

globular, polar, reddish or yellowish brown

when young, darkening to mahogany brown,

opaque; wing 7.5 pm wide, with pore at margin-

al angles, margin crenulate and somewhat erod-

ed; ornamentation reticulate or reticulate-foveo-

late, rather different on 2 spore faces; distal face

with (9— )10(— 1 2) deep, cup-like alveoli across

diam., 10.0-12.5 pm wide, smaller toward mar-

gin, walls thickened, slightly raised at nodes,

encrusted with granules and papillae, sometimes

smoother; proximal face with triradiate mark not

sharply defined, often partly obscured by dense

granules, each facet with 15-20 small, shallow

alveoli, ± 5 pm wide, some adjacent ones con-

fluent, walls low, slightly raised at nodes, heav-

ily sprinkled with granules to rather smoother.

Chromosome number : n = 8 (Bornefeld 1984).

Plate 16E, F; Perold (1989e: fig. 43.1-6).

The species is endemic to the arid shrublands

of the Northern and Western Cape, where it is

quite rare. It is found on decomposed granite, at

seepages or at margins of flat rock outcrops.

Map 18.

The unique composition of the dorsal epider-

mis necessitated placing this species in the

HEPATOPHYTA: RlCCJACEAE

153

A

monotypic subgenus Chartacea. Riccia schelpei

is characterized by the somewhat greasy ap-

pearance of the dorsal epidermis when fresh,

with air pores surrounded by a ring of smaller,

fragile cells superimposed over thicker-walled

cells, giving it a mottled appearance; on drying

out, the dorsal face turns yellowish and parch-

ment-like, the groove is deep and the margins

winged. Since the initial description (Volk &

Perold 1986b), several more collections have

been made and the distribution area expanded.

A note by Duthie, found with a specimen of R.

schelpei, Giffen 3 (PRE-CH 1056), which had

previously been identified as R. bullosa (no. 5)

(see note under that species), contained the fol-

lowing information: ‘not correctly named, but I

am not at present able to identify it; probably a

new species, with shape of thallus as in R. cili-

ifera, but spores different’.

Vouchers: Oliver 8041 (PRE); S.M. Perold

1480, 1946, 2178 (PRE); CM. van Wyk 2524

(PRE).

Figure 39. — Riccia schelpei. A, B, thallus: A, wet; B, dry. C, thick-walled epidermal cells seen from above, with small,

thin-walled cells surrounding air pores (hatched), air chambers below partly stippled; D, c/s epidermis and assimilation tis-

sue; E, c/s branch; F, scale. A, S.M. Perold 1422 p.p.; B, S.M. Perold 2052', C-E, Oliver 504 1 ; F, C M. van Wyk 2524. Scale

bars: A, B, E, I mm; C, D, 50 pm; F, 100 pm. Artist: J. Kimpton.

154

HEPATOPHYTA: Ricci ACEAE

E. Subgenus Riccia

Thalli small to large; terricolous; groove deep or shallow, margins ciliate or glabrous. Scales lat-

eral, rarely ventral, mostly large, extending to, or projecting above thallus margins, rounded, very

occasionally triangular, variously pigmented or hyaline, scale margins entire, rarely denticulate or

crenate.

Dorsal epithelium hyaline, in one or more strata; air pores as small spaces, numerous, regular.

Assimilation tissue compact, with mostly narrow, interstitial, vertical air canals.

Spores large, (65-)80-120 pm in diam.; tetrads separating at maturity, triangular-globular or

subglobose, variously ornamented.

El. Section Riccia

Thalli small to large; terricolous; groove apical or along entire length of branches, margins cil-

iate or glabrous. Scales generally large, hyaline or variously pigmented, margins mostly entire,

rarely crenate.

Dorsal epithelium in 1 or 2 strata, cells in close association, top cells mostly globose or pyri-

form along groove or apically, soon collapsing, rarely persistent.

Three informal groups are recognized within this section: Ciliatae, Mammillatae and

Squamatae.

El.l. Group Ciliatae

Thallus margins ciliate. Scales small, not, or hardly extending to thallus margins.

15. Riccia trichocarpa M.Howe in Bulle-

tin of the Torrey Botanical Club 25: 184 (1898);

M.Howe: 18 (1899); Frye & L.Clark: 27 (1937);

Jovet-Ast: 39 (1983); Jovet-Ast: 332 (1986);

Perold: 26 (1991c); Jovet-Ast: 227 (1991). Type:

Calif., Santa Clara Co. near San Mateo Co. line

[fide M.Howe: 18 (1899)], April 1892, D.H.

Campbell s.n. [US, holo., fide Jovet-Ast: 332

(1986); NY, iso.!].

R. canescens Steph.: 320 (1898); Mull.Frib.: 445

(1951-1958); S.W.Amell: 16 (1963a). Type: Algeria, Oran,

Balansu s.n., 1 852.

Thalli smallish to medium-sized, in com-

plete or incomplete rosettes, up to 20 mm across

or in crowded, gregarious patches; bright green

to glaucous green, margins with long cilia,

flanks dark purple; when dry, margins inflexed,

cilia covering dorsal face. Branches 2-4 times

furcate, shortly to deeply divided, almost paral-

lel to narrowly divergent, linear-ovate or ligu-

late, 2.5-5.5(-7) x 0.9-1. 5 mm, 0. 6-0.9 mm

thick, in section as wide as thick to 1.5 times

wider than thick, apex rounded to shortly emar-

ginate; groove distally deep and narrow, shal-

low and wider proximally, lateral sides convex,

gradually flattening out, thallus margins round-

ed; flanks somewhat bulging to steeply ascend-

ing, dark purple; ventral face slightly convex to

nearly flat with narrow, transverse bands of vio-

let or brown vestigial scales. Cilia in several

rows at margins and flanks, along entire length

of branches, crowded at apex, hyaline, smooth,

rather shiny, stiff and straight to slightly flexu-

ose, 450-750(-950) pm long, (40-)50 pm wide

at base, gradually narrowing to sharply pointed

apex, spirally twisted with margins alternately

inflexed, appearing thick-walled. Scales tightly

HEPATOPHYTA: Ricciaceae

155

adherent to, or fused with Hanks, not detachable

and not extending above margins of thallus,

purple to nearly black.

Dorsal epithelium unistratose, cells globose

to mammillose, 35-45 x 35-40 pm, hyaline,

fragile, soon collapsing; air pores small, trian-

gular or 4-sided. Assimilation tissue 300-400

pm thick, consisting of vertical columns of 7 or

8 isodiametric cells, enclosing narrow air

canals; storage tissue occupying ventral part of

thallus, cells closely packed, rounded, ± 45 pm

wide. Figure 40.

Perennation by bulbils.

Monoicous. Antheridia along groove, with

projecting hyaline necks up to 50 pm long.

Archegonia scattered, necks purple. Sporangia

bulging dorsally, with central purple spot,

crowned with 2-10 cilia, in groups of 2 or 3.

Spores 100-120 pm diam., triangular-globular,

polar, very dark brown to black, opaque; wing-

less, marginal angles with pores, margin finely

crenulate; ornamentation reticulate and similar

on 2 spore faces, alveoli extending to margin;

distal face convex, ( 1 0—) 1 2— 1 4 rounded alveoli

across diam., 7.5-10.0 pm wide, alveolar walls

thick, heavily encrusted with small to large

wart-like papillae, and stout, blunt tubercles

projecting mostly from central nodes, 5. 0-7. 5

pm long; proximal face with triradiate mark

indistinct, ± 30 alveoli on each of 3 facets, up to

5 pm wide, walls heavily granulate. Chromo-

some numbers: n = 8; 16 (Jovet-Ast 1983;

1986); 16 (Bornefeld 1984; 1989). Plate 17A,

B; Perold (1989e: fig. 3.1-6).

The species is widespread and subcosmo-

politan; it is known from countries bordering

the Mediterranean, Macaronesia, Kenya, Ma-

lawi, Niger, Tanzania, Uganda, Zimbabwe,

Madagascar, North and South America. The

Australian species, R. crinita Taylor, may yet

prove to be conspecific (Jovet-Ast 1986).

In the FSA area, R. trichocarpa has been found

throughout the semi-arid savanna/grassland

biome of Namibia, but rarely in Botswana,

Northern Province, North-West, Free State,

Lesotho, Northern and Eastern Cape. It grows on

shallow, sandy soil overlying quartzite or

dolomite outcrops or on calcareous crust. Map 18.

Riccia trichocarpa is recognized by the con-

spicuous, long, smooth, marginal cilia, purple

Hanks and dark brown to black spores, with

densely granulate alveolar walls.

Jovet-Ast (1986) distinguished between cilia

and hairs (‘pods’), the latter being thin-walled

and stouter. Riccia canescens Steph. was placed

in synonymy under R. trichocarpa (Jovet-Ast

1983), as the thalli are indistinguishable from

each other. Volk (1984) reported the species (as

R. canescens) to have a preference for alkaline

soils, whereas Jovet-Ast (1986) gave soil pH

values of 4.5-6. 3 (rarely 7. 0-7. 5), which indi-

cates a wide tolerance. Schuster (1992b) treats

R. trichocarpa (and R. canescens) as subspecies

of R. ciliata, but this has not been accepted here.

Vouchers: Duthie 5494 (BOL); S.M. Perold

748 (PRE); Toelken 5561 (PRE); O.H. Volk

81/293 p.p. (M; PRE).

16. Riccia crozalsii Levier in Revue bry-

ologique et lichenologique 29: 73 (1902);

Macvicar: 16 (1926); Miill.Frib.: 447 (195 1 —

1958); S.W.Arnell: 284 (1956a); S.W.Arnell: 17

(1963a); E.O.Campb.: 223 (1977); Na-Thalang:

80 (1980); Jovet-Ast: 337 (1986); Perold: 27

(1991c). Type: France, Herault, prope Roque-

haute (Agde), Crozals March 1902 (?FI);

Crozals specimens March-May 1902 [PC, syn.

fide Jovet-Ast: 337 (1986)].

R africana Sim: II (1926). Type: Cape, Stellenbosch

flats, Garside 8 ( PRE-CH1065 ) [PRE, lecto.!, selected by

Perold (1991c)].

R. ciliata Hoffm. var. austroafricana S.W. Amell: T.XXII,

fasc. 1-2 (1953a).

R. crozalsii var. austroafricana S.W. Amell: 18 (1963a).

Thalli smallish to medium-sized, in scat-

tered or incomplete rosettes 15-20 mm across;

pale green or glaucous-green, sometimes with

156

HEPATOPHYTA: RlCClACEAE

Figure 40. — Riccia trichocarpa. A, B, thallus: A, wet; B, dry. C, ventral face of branch; D, c/s branch at intervals

from apex to base; E, epithelial cells and air pores (hatched), seen from above; F, c/s epithelial and assimilation tissue

cells; G, cilia. A-G, Henderson 658. Scale bars: A-D, 1 mm; E-G, 50 pm. Artist: J. Kimpton.