Bothalia

’N TYDSKRIF VIR PLANTKUNDIGE NAVORSING

A JOURNAL OF BOTANICAL RESEARCH

Vol. 16,2 OCT./OKT. 1986

PUBLICATIONS OF THE BOTANICAL RESEARCH INSTITUTE

PUBLIKASIES VAN DIE NAVORSINGSINSTITIJUT VIR PLANTKUNDE

Obtainable from the Division of Agricultural Information, De-

partment of Agriculture and Water Supply, Private Bag X144,

Pretoria 0001, Republic of South Africa. A current price list of

all available publications will be issued on request.

Verkrygbaar van die Afdeling Landbou-inligting, Departement

van Landbou en Watervoorsiening, Privaatsak X144, Pretoria

0001, Republiek van Suid-Afrika. ’n Geldige lys van alle beskik-

bare publikasies kan aangevra word.

BOTHALIA

Bothalia is named in honour of General Louis Botha, first Premier

and Minister of Agriculture of the Union of South Africa. This

house journal of the Botanical Research Institute is devoted to

the furtherance of botanical science. The main fields covered

are taxonomy, ecology, anatomy and cytology. One or two parts

of the journal are published annually.

Bothalia is vemoem ter ere van Generaal Louis Botha, eerste Eerste

Minister en Minister van Landbou van die Unie van Suid-Afrika

Hierdie lyfblad van die Navorsingsinstituut virPlantkunde isgewy

aan die bevordering van die wetenskap van plantkunde. Die hoof-

gebiede wat gedek word, is taksonomie, ekologie, anatomie en

sitologie. Een of twee dele van die tydskrif verskyn jaarliks.

MEMOIRS OF THE BOTANICAL SURVEY OF SOUTH AFRICA

MEMOIRS VAN DIE BOTANIESE OPNAME VAN SUID-AFRIKA

The memoirs are individual treatises usually of an ecological ’n Reeks van losstaande omvattende verhandelings oorvernaam-

nature, but sometimes dealing with taxonomy or economic lik ekologiese, maar soms ook taksonomiese of plantekonomiese

botany. onderwerpe.

THE FLOWERING PLANTS OF AFRICA / DIE BLOMPLANTE VAN AFRIKA

This serial presents colour plates of African plants with ac-

companying text. The plates are prepared mainly by the artists

at the Botanical Research Institute. Many well-known botanical

artists have contributed to the series, such as Cythna Letty (over

700 plates), Kathleen Lansdell, Stella Gower, Betty Connell,

Peter Bally and Fay Anderson. The Editor is pleased to receive

living plants of general interest or of economic value for illustra-

tion.

Two parts of ten plates each are published annually. A volume

consists of four parts. The publication is available in English and

Afrikaans.

Hierdie reeks bied kleurplate van Afrikaanse plante met bygaan-

de teks. Die skilderye word meestal deur die kunstenaars van die

Navorsingsinstituut vir Plantkunde voorberei. Talle bekende bota-

niese kunstenaars het tot die reeks bygedra, soos Cythna Letty

(meer as 700 plate), Kathleen Lansdell, Stella Gower, Betty Con-

nell, Peter Bally en Fay Anderson. Die Redakteur verwelkom

lewende plante van algemene belang of ekonomiese waarde vir

afbeelding.

Twee dele, elk met 10 plate, word jaarliks aangebied. ’n Volume

bestaan uit vier dele. Die publikasie is beskikbaar in Afrikaans en

Engels.

FLORA OF SOUTHERN AFRICA / FLORA VAN SUIDELIKE AFRIKA

A taxonomic treatise on the flora of the Republic of South Africa,

Ciskei, Transkei, Lesotho, Swaziland, Bophuthatswana, South

West Africa/Namibia, Botswana and Venda. The FSA contains

descriptions of families, genera, species, infraspecific taxa, keys

to genera and species, synonymy, literature and limited specimen

citations, as well as taxonomic and ecological notes. Also available

in the FSA series are the following:

’n Taksonomiese verhandeling oor die flora van die Republiek

van Suid-Afrika, Ciskei, Transkei, Lesotho, Swaziland, Bophu-

thatswana, SWA/Namibie, Botswana en Venda Die FSA bevat

beskry wings van families, genusse, spesies, infraspesifieke taksons,

sleutels tot genusse en spesies, sinonimie, literatuur, verwysings

na enkele eksemplare, asook beknopte taksonomiese en ekologiese

aantekeninge. Ook beskikbaar in die FS A-reeeks is die volgende :

The genera of southern African flowering plants by/deur R.A. Dyer, Vol. 1 Dicotyledons (1975); Vol. 2

Monocotyledons (1976).

Keys to families and index to the genera of southern African flowering plants by/deur R.A. Dyer (1977).

Plant exploration of southern Africa by Mary Gunn & L.E. Codd. Obtainable from/Beskikbaar van:

A. A. Balkema, Box/Bus 3117, Cape Town/Kaapstad 8000, RSA.

PALAEOFLORA OF SOUTHERN AFRICA / PALAEOFLORA VAN SUIDELIKE AFRIKA.

A palaeofiora on a pattern comparable to that of the Flora of

Southern Africa Much of the information is presented in the

form of tables and photographic plates depicting fossil popula-

tions. Now available:

’n Palaeofiora met ’n uitleg vergelykbaar met die van die Flora

van Suidelike Afrika. Baie van die inligting word aangebied in die

vorm van tabelle en fotografiese plate waarop fossiele populasies

afgebeeld word. Reeds beskikbaar:

Molteno Formation (Triassic) Vol. 1 Introduction. Dicroidium by/deur J.M. & H.M. Anderson.

Prodromus of South African Megafloras. Devonian to Lower Cretaceous by/deur J.M. & H.M. Anderson.

Obtainable from/Beskikbaar van: A.A. Balkema, Box/Bus 3117, Cape Town/Kaapstad 8000, RSA.

Republic of

South Africa

Republiek van

Suid-Afrika

BOTHALIA

N TYDSKRIF VIR PLANTKUNDIGE NAVORSING

A JOURNAL OF BOTANICAL RESEARCH

Volume 16,2

Editor/Redakteur: O. A. Leistner

Editorial Board/Redaksieraad

D. F. Cutler

B. de Winter

D. J. B. Killick

O. A. Leistner

P. H. Raven

J. P. Rourke

M. J. Werger

Royal Botanic Gardens, Kew, UK

Botanical Research Institute, Pretoria, RSA

Botanical Research Institute, Pretoria, RSA

Botanical Research Institute, Pretoria, RSA

Missouri Botanical Garden, St Louis, USA

National Botanic Gardens, Kirstenbosch, RSA

University of Utrecht, Utrecht, Netherlands

ISSN 0006 8241

Published by the Botanical Research Institute, Department of Agriculture and Water Supply, Private Bag X101,

Pretoria 0001, South Africa

Uitgegee deur die Navorsingsinstituut vir Plantkunde, Departement van Landbou en Watervoorsiening,

Privaatsak X101, Pretoria 0001, Suid-Afrika

1986

Digitized by the Internet Archive

in 2016

https://archive.org/details/bothaliavolume1616unse_0

CONTENTS — INHOUD

Volume 16,2

1. The taxonomy, chorology and reproductive biology of southern African Meliaceae and Pteroxyla-

ceae. F. WHITE 143

2. Studies in the genus Riccia (Marchantiales) from southern Africa. 4. Three endemic species,

R. natalensis, R. microciliata, sp. nov. and R. mammifera, sp. nov. O. H. VOLK and S. M.

PEROLD 169

3. Studies in the genus Riccia (Marchantiales) from southern Africa. 5. R. rosea, a new species. O. H.

VOLK and S. M. PEROLD 181

4. Studies in the genus Riccia (Marchantiales) from southern Africa. 6. R. hirsuta, a new species, in a

new section. O. H. VOLK and S. M. PEROLD 187

5. Studies in the genus Riccia (Marchantiales) from southern Africa. 7. R. congoana and its synonyms.

S. M. PEROLD 193

6. Numerical taxonomic studies in the subtribe Ruschiinae (Mesembryanthemaceae) — Astridia,

Acrodon and Ebracteola. H. F. GLEN 203

7. Notes on African plants:

Asclepiadaceae. The nomenclature of several Brachystelma species from southern Africa. P. I.

FORSTER 227

Asteraceae. A new record for Natal and the southern African flora region. G. GERMISHUI-

ZEN 228

Ebenaceae. A new species of Euclea from the Transvaal. E. RETIEF 228

Fabaceae. A new species of Indigo fera from the southern Cape. J. K. JARVIE and C. H.

STIRTON 230

Fabaceae. A new record for Natal and the southern African flora region. G. GERMISHUI-

ZEN 231

Liliaceae. Notes on Kniphofia. L. E. CODD 231

Polygonaceae. Raising the rank of Polygonum senegalense forma albotomentosum to subsp.

albotomentosum. G. GERMISHUIZEN 232

Polygonaceae. Bilderdykia and Reynoutria new to the flora of the southern African region. G.

GERMISHUIZEN 233

8. Leaf anatomy of the South African Danthonieae (Poaceae). XIV. Pentameris dregeana. R. P. EL-

LIS 235

9. Leaf anatomy of the South African Danthonieae (Poaceae). XV. The genus Elytrophorus. R. P.

ELLIS 243

10. The biomes of the eastern Cape with emphasis on their conservation. R. A. LUBKE, D. A. EVER-

ARD and SHIRLEY JACKSON 251

11. A method for vegetation stratification using scale-related vegetation-enhanced satellite imagery.

R. H. WESTFALL and O. G. MALAN 263

12. Miscellaneous notes:

Chromosome studies on African plants. 2. J. J. SPIES and H. DU PLESSIS 269

PHYTOLOC — a random-number generator and sample-set location program for stratified

random vegetation sampling. R. H. WESTFALL 270

13. Book Reviews 273

14. Guide for authors to Bothalia 275

Bothalia 16,2: 143-168 (1986)

The taxonomy, chorology and reproductive biology of southern Afri-

can Meliaceae and Ptaeroxylaceae

F. WHITE*

Keywords: chorology, Meliaceae, Ptaeroxylaceae, reproductive biology, southern Africa, taxonomy

ABSTRACT

Information is provided on the taxonomy, chorology and reproductive biology of 14 indigenous and two intro-

duced species of Meliaceae in southern Africa, and on Ptaeroxylon (Ptaeroxylaceae). Two new taxa are described:

Nymanieae F. White, tribus nov. and Turraea streyi F. White & B. T. Styles, sp. nov. Nurmonia (Harms) F. White,

comb, et stat. nov., a new section of Turraea L. is created. The account complements the treatments of these

families in the Flora of southern Africa.

UITTREKSEL

Inligting word verskaf oor die taksonomie, chorologie en voortplantingsbiologie van 14 inheemse en twee inge-

voerde spesies van Meliaceae in suidelike Afrika en oor Ptaeroxylon (Ptaeroxylaceae). Twee nuwe taksons word

beskryf: Nymanieae F. White, tribus nov. en Turraea streyi F. White & B. T. Styles, sp. nov. Nurmonia (Harms) F.

White, comb, et stat. nov., ’n nuwe seksie van Turraea L. word geskep. Hierdie verslag is aanvullend tot die

behandelings van hierdie families in die Flora of southern Africa.

CONTENTS

Introduction 143

Generic and family delimitation 144

The position of Ptaeroxylon 144

The position of Nymania 144

The circumscription of Turraea 145

Notes on individual genera and species

1. Nymania 146

N. capensis 146

2. Turraea

Sectio Turraea 148

1. T. nilotica 149

2. T. zambesica 149

3. T. obtusifolia 149

4. T. floribunda 151

Sectio Nurmonia 151

5. T. pulchella 151

6. T. streyi 153

3. Melia 154

M. azedarach 154

4. Azadirachta

A. indica 155

5. Ekebergia

1. E. capensis 155

2. E. pterophylla 157

6. Trichilia 157

7. Pseudobersama

P. mossambicensis 161

8. Entandrophragma 162

1. E. caudatum 162

2. E. spicatum 162

Discussion

Chemistry and the taxonomy of Meliaceae

Introduction 162

Limonoids and the Meliaceae 163

* Department of Plant Sciences, University of Oxford, South

Parks Road, Oxford 0X1 3RA, United Kingdom.

The position of Ptaeroxylon and Nyma-

nia 163

South African Trichilia : chemistry and

the taxonomist’s eye 163

Conclusions 163

Taxonomy as a visual art 163

The Meliaceae and the chorology of south-

ern Africa 164

The function of taxonomic characters 165

Acknowledgements 166

References 166

INTRODUCTION

This paper should be read in conjunction with the

accounts of Meliaceae and Ptaeroxylaceae in the

Flora of southern Africa (White & Styles, in press, a

& b). In the latter, descriptions are brief and little

ancillary information is provided. In the present ac-

count three new taxa (the tribe Nymanieae, the sec-

tion Nurmonia of Turraea and the species Turraea

streyi ) are described. Reasons are given for the taxo-

nomic decisions on which the flora accounts are

based. The geographical patterns of variation in

Ekebergia capensis and Turraea obtusifolia are

analysed and evaluated. The two southern African

species of Trichilia , T. dregeana and T. emetica,

have a complex and confused taxonomic and nomen-

clatural history. This is unravelled at some length.

In its ecology the Meliaceae is more diverse than

most tropical families of comparable size, particu-

larly with regard to pollination and dispersal. This is

also true for the subtropical, southern African mem-

bers. What little is known about this subject is

briefly described under each species, and sugges-

tions are made for further work.

In the discussion at the end of the paper the south-

ern African Meliaceae are used to illustrate certain

themes of general biological interest — in particular

144

Bothalia 16,2 (1986)

the contributions that chemistry and field ecology

can provide. Some comments are also made on the

methods of taxonomic research. The fact that taxo-

nomy is basically a visual art is emphasized.

In the descriptions the term aril is used in an eco-

logical rather than in a precise anatomical sense;

minor variation in the number of floral parts is ig-

nored.

GENERIC AND FAMILY DELIMITATION

For its size the Meliaceae probably contains a

wider range of floral and fruit structures than any

comparable group (White in Pennington & Styles

1975: 419). It is also diverse in vegetative morpho-

logy. Diversity of the flower and fruit is related to

the wide variety of pollen vectors and agents of dis-

persal, though, with only a few exceptions (e.g. Pan-

nell & Koziol, in press), this has been little studied.

Comparative studies within the family indicate

that it has retained a primitive type of fruit, in this

case a capsule with brightly coloured, bird-dis-

persed, arillate seeds, and that all other fruit types in

the family are derived (Pannell & White 1985: 1).

Primitive fruits persist alongside the advanced and

this provides clues to the pathways of evolutionary

change. The situation is similar for the meliaceous

flower.

Persistence, or lack of extinction of the kind found

in Meliaceae, poses taxonomic problems. It has

given rise to some extremely variable groups which

are difficult to define taxonomically, especially when

the function of the characters used in classification is

not understood.

Because of the nature of its variation pattern, the

Meliaceae has had a long history of taxonomic insta-

bility, succinctly described by Pennington (in Pen-

nington & Styles 1975). He gives special considera-

tion to genera whose inclusion in the family has been

controversial. Among them, he concludes that Ny-

mania belongs to Meliaceae, but, following Leroy

(1959, 1960) and White & Styles (1963, 1966), that,

Ptaeroxylon should be removed from that family. In

general, Pennington’s views have been followed, but

in some publications (e.g. Airy Shaw 1966, 1973;

Dyer 1975) Nymania is excluded and Ptaeroxylon

(Dyer 1975) retained. More recent data especially

from phytochemistry, support Pennington’s conclu-

sions.

The Meliaceae is poorly represented in southern

Africa. It is therefore difficult, in a purely local con-

text, to assess the relationships of anomalous genera

such as those mentioned above. For that reason the

evidence for including the one genus and not the

other is summarized below. Two South African

species of Turraea occupy an isolated position within

it, and their relationships are also discussed.

The position of Ptaeroxylon

Since Ptaeroxylon was first described (Ecklon &

Zeyher 1834-35), its taxonomic position has been

uncertain. In their protologue, the original authors

suggest that its true affinities may be with Rutaceae,

but they tentatively grouped it with Sapindaceae ‘un-

til such time as it could be studied by more experi-

enced botanists’.

As long ago as 1860, Sonder (1860: 242), placed it

immediately after Sapindaceae as a genus of uncer-

tain affinity, and indirectly indicated that it might

qualify for family rank. According to Leroy (1960),

Sonder’s name ‘Ptaeroxyleae’ should be regarded as

a nomen provisorium, though Airy Shaw (1966,

1973) cites Sonder as the legitimate author of Ptae-

roxylaceae. Leroy, who had elsewhere (1959) dis-

cussed the taxonomy of Ptaeroxylon together with

the Malagasy genus Cedrelopsis Baillon, concluded

that, in their morphology, secondary xylem and pol-

len, these genera are so distinct that family rank,

which he formally proposed, is required. White &

Styles (1966), partly using evidence from an unpub-

lished thesis (Jenkin 1961), independently reached a

similar conclusion.

During the hundred years between 1860 and 1960

Ptaeroxylon was usually placed, sometimes with re-

servations, either in Sapindaceae (Hooker 1862;

Phillips 1921; Mauritzon 1936) or Meliaceae (Radl-

kofer 1890; Harms 1896, 1940; Phillips 1951), where

Dyer (1975) allowed it to remain.

In a comprehensive review of all the evidence then

available, Pennington & Styles (1975) showed that

Ptaeroxylon and Cedrelopsis share a few features

with Meliaceae, Rutaceae and Sapindaceae, but are

so different in other respects that the family Ptaerox-

ylaceae should be retained.

According to Taylor (1983; see also Dean & Tay-

lor 1966) Ptaeroxylon and Cedrelopsis are suffi-

ciently distinct in their chemistry to form a separate

family. Limonoids, a group of oxidized triterpenes

which occur in Rutaceae, Meliaceae, Cneoraceae

and in Harrisonia abyssinica (Simaroubaceae), are

unknown in Ptaeroxylaceae. However, absence may

not be very significant. What is much more import-

ant is that Ptaeroxylaceae does contain many other

unusual compounds not found in any Meliaceae,

most notably chromones of the ptaeroxylin group.

These substances otherwise have been found only in

Cneoraceae and in Spathelia and Harrisonia (Sima-

roubaceae). The former is usually placed in Rutaceae

though some botanists think it would be better ac-

commodated in Simaroubaceae.

The position of Nymania

Nymania, in its fasciculate, linear, sclerophyllous

leaves, almost free staminal filaments and large in-

flated capsules, is so different in appearance from

other southern African Meliaceae that it is not sur-

prising that some botanists who were concerned pri-

marily with the flora of South Africa should have

been tempted to exclude it from that family (Sonder

1860; Dyer 1975). Recent specialists of the Melia-

ceae, however, have been virtually unanimous on its

inclusion, (e.g. Harms 1940; Pennington & Styles

1975), following the lead of Antoine Laurent de Jus-

sieu (1789) and Ventenat (1799). Adrien de Jussieu

(1830), however, in his early monograph of the fam-

ily, was unsure of its affinity, and mentioned that a

correspondent, M. Gay, thought it to be close to Sa-

pindaceae.

Bothalia 16,2 (1986)

145

Some authors of general systems of classification

of flowering plants, who lacked detailed knowledge

of the group, have, however, placed Nymania (or its

illegitimate synonym, Aitonia, see below) in other

families, including Sapindaceae (tribe Dodonaeeae,

Hooker 1862), or have suggested family rank (Airy

Shaw in Willis 1966, 1973) as Aitoniaceae. One has

expressed doubt concerning its systematic position

(Sonder 1860).

Radlkofer (1890), the great authority on Sapinda-

ceae, discusses the affinity of Nymania at some

length and concludes that a relationship with the

Meliaceae is very close. The resemblance between

the fruit of Nymania and that of Melianthus (Melian-

thaceae, a satellite of Sapindaceae) or Dodonaea

was shown to be superficial. Many other characters,

notably the 4-merous flowers, antisepalous position

of the carpels, endospermous seed, curved embryo

and intra-staminal disk, would not exclude it from

the Meliaceae. Radlkofer notes in particular, that

the continuous ring of sclerenchymatous tissue,

which is present in the bark of the twigs of Sapinda-

ceae, is absent from Nymania as in all other Melia-

ceae.

Pennington (in Pennington & Styles 1975) has stu-

died Nymania in great detail in relation to all other

genera of Meliaceae and to related families. He has

shown that:

(1) most features of the pollen of Nymania are

shared by members of the tribe Turraeeae;

(2) Nymania has secondary xylem which is very

similar to that of Calodecaryia and some species of

Turraea, thus confirming its position in the Melia-

ceae, but it has other characters, namely the very

small vessels and sparse or absent paratracheal par-

enchyma, found nowhere else in the family;

(3) in its foliage and seed structure, the Malagasy

genus Calodecaryia links Nymania to other Melia-

ceae.

In its chemistry, Nymania unequivocally belongs

to the Meliaceae (Taylor 1983, 1984, pers. comm.;

Maclachlan & Taylor 1982). Nearly every member

of the family so far investigated has been found to

contain one or more limonoids (p. 163). At the

family level the chemotaxonomic distinctions are

very clear. Nymania contains limonoids belonging to

the Evodulone and Prieurianin groups. Those of the

former are also found in species of Carapa, Toona

and Trichilia, whereas the latter occur in Aphana-

mixis, Guarea, Toona and Trichilia.

In conclusion there can be little doubt that the

best place for Nymania is in the Meliaceae. Because

of its isolation , however, tribal rank seems justified .

Tribus Nymanieae, tribus nova

Meliaceae'. Aitonieae M. J. Roemer: 88 (1846),

nom. illegit. (see p. 146).

Aitonieae Harvey: 243 (1860), nom. provis. et il-

legit.

Aitoniaceae Airy Shaw: xxi (1966), nom. illegit.

Folia simplicia, fasciculata, sclerophylla. Sepala 4.

Petala 4. Stamina 8; filamenta solum basi coniuncta.

sine appcndiculis; antherae medifixae. Ovarium 4-

lobatum, loculis 4 praeditum. Ovula in loculo quo-

que bina, collaterals, parvo arillo carnoso ante

seminis maturitatem fatiscente. Semen reniforme.

Embryo valide curvata, tenui endospermio inclusa.

Typus tribus: Nymania

Leaves simple, fasciculate, sclerophyllous. Sepals

4. Petals 4. Stamens 8; filaments united only at the

base, without appendages; anthers medifixed. Ovary

4-lobed, with 4 locules. Ovules 2 in each locule, col-

lateral, with a small fleshy aril which disintegrates

before the seed reaches maturity. Seed reniform.

Embryo strongly curved, embedded in thin endo-

sperm.

The circumscription of Turraea

The majority of species of Turraea in tropical

Africa have the following features:

simple leaves;

long and narrow, white or whitish petals;

an elongate staminal tube terminated by 10 or

more appendages or a staminal frill;

an exserted style with an expanded style-head

which is stigmatic only near the apex;

a loculicidal capsule containing reniform arillate

seeds.

These characteristics are also found in some Mal-

agasy and Far Eastern species.

There is evidence that in most species the flowers

are fragrant at night and are pollinated by moths,

though in some species, e.g. T. fischeri Giirke, birds

may be responsible (White & Styles 1963: 307). It is

possible that in most species the style-head functions

as a pollen-presenter or receptaculum pollinis,

though confirmation in the field is needed. The de-

velopment of the aril varies greatly, though it is al-

ways relatively small, and it seems that the seeds,

and sometimes parts of the capsule, are to some de-

gree mimetic.

Certain species which are evidently closely related

to Turraea sens, strict, lack one or more of its unify-

ing features. Whether they should be included or not

has sometimes been a matter of controversy. In cer-

tain cases the differences from typical Turraea ap-

pear to be related to different methods of pollination

or dispersal, though in the absence of field studies

this important subject will remain conjectural.

Pennington (in Pennington & Styles 1975: 446)

has discussed the difficulty of generic delimitation in

the Meliaceae, and advocates a pragmatic middle

course between excessive lumping and excessive

splitting, a case for each of which could be made on

theoretical grounds.

In the subfamily Melioideae Pennington found

that the majority of genera fall into four tribes (Tur-

raeeae, Trichilieae, Aglaieae and Guareeae) which

show a similar variation pattern. The majority of

species in each tribe belong to a single genus, which,

although it contains much variation, is still definable

and cannot be satisfactorily split. The remaining

species form a number of small satellite genera. In

the Turraeeae, the satellite genera are as follows:

146

Bothalia 16,2 (1986)

Munronia Wight, c. 10 species in India and Ma-

lesia; Naregamia Wight & Arn., 1 species in Angola,

1 species in India; Humbertioturraea J. F. Leroy, 3-4

species in Madagascar; Calodecaryia J. F. Leroy,

1-2 species in Madagascar; Nymania Lindb., 1

species in southern Africa.

Pennington includes in Turraea certain species

which form isolated groups within it; the latter ap-

pear to be less distinct than the satellite genera men-

tioned above. In this he partly follows Harms (1940)

who demoted Quivisia Commers. ex Juss., Calo-

dryum Desv. and Grevellina Baill. to sectional rank.

Pennington also united with Turraea the monotypic

genus Nurmonia Harms, based on the southern Afri-

can N. pulchella, which Harms kept separate.

In revising Meliaceae for the Flora of southern

Africa it was necessary to study T. pulchella along-

side a new species, T. streyi, which is closely related

to it and to reconsider the status of Nurmonia.

The isolated position of these two species in Tur-

raea is confirmed. There are striking differences in

the flowers and fruits which appear to be related to

pollination and dispersal, and this may also be the

case for other isolated groups within Turraea, e.g.

Quivisia, and for some of the satellite genera.

It could be argued that the differences separating

T. pulchella and T. streyi from typical Turraea are at

least as great as those characterizing, say, the satel-

lite genus Naregamia, and that Nurmonia should be

restored to generic rank. In my opinion, in our pres-

ent state of knowledge, such a view would be inad-

visable. Until the biological significance of the dis-

tinguishing features of the satellite genera and

anomalous species have been carefully studied and

correctly interpreted, a generic re-assessment would

serve little purpose. In the meantime, in order to fo-

cus attention on the problem and to emphasize the

need for further study, especially in the field, the

section Nurmonia is proposed below (p. 151)

where its constituent species are described in as

much detail as the rather sparse material allows.

NOTES ON INDIVIDUAL GENERA AND SPECIES

1. NYMANIA Lindb.

Nymania Lindb. in Notiser ur Sallskapets pro

Fauna et Flora Fennica Forhandlingar 9: 290 (1868);

Marloth: 112, 114, fig. 40d (1925); Harms: 94, fig. 24

(1940); Dyer: 299 (1975); Pennington & Styles: 460,

fig. 4c (1975). Type species: N. capensis (Thunb.)

Lindb.

Aitonia Thunb.: (T776’) 166, fig. 3 (1781);

Thunb.: 52 (1782); Thunb.: 508 (1823); Sond.: 243

(1860); nom. illegit. non Aytonia J. R. & J. G. A.

Forster (1776) Marchantiaceae).

Aytonia L.f.: 49, 303 (1781), emend. Aitonia p.

468.

Carruthia Kuntze: 141 (1891).

Marloth (1925) correctly observed that the genus

Aitonia was named after William Aiton, gardener to

King George III, and that Aitonia Thunb. ‘is not va-

lid as ‘Aitonia’ Forst. (Marchantiaceae) was estab-

lished in 1776’.

The name Aitonia Thunberg appears in most pha-

nerogamic literature until the end of the nineteenth

century, and Harms (1896) used it in his account of

Meliaceae in Die Natiirlichen Pflanzenfamilien

though he adopted Nymania in the Nachtrdge of that

work (11:36, 1900). During the same period Aytonia

Forster had also been popular among bryologists. In

1930, however, Schiffner proposed Plagiochasma

Lehmann & Lindenberg (1832) as a nomen conser-

vandum versus Aytonia of which he says ‘descriptio

omnino falsa’ (Rehder in Rehder et al. 1935:

349-350), and this recommendation was subse-

quently adopted.

Rehder was unable to recommend that Aitonia

Thunberg could be conserved and accepted Nyma-

nia as the correct name for it. Most subsequent

authors have concurred.

According to St. John (1971) the Ayton of the

Forsters and the Aiton of Thunberg are two different

individuals, but this view is untenable since Thun-

berg (1782) says ‘in honorem Dom. Aiton, Hortu-

lani in Horto Regio Kewensi’ while Forster says

‘Dedimus a Joanne Ayton — Hortulano primario

Regis Magnae Britanniae in horto Botanico Ke-

wensi’.

The title pages of the works in which Aitonia

Thunberg and Aytonia Forster appear give the same

date (1776), but according to Karsten (1946) Thun-

berg’s protologue was not published until 1781. St.

John (1971: 568) has also found evidence that the

first edition of Forster’s Characteres was published in

1775, but in a limited edition of six copies, only two

of which survive.

In conclusion, Aitonia of Thunberg is illegitimate

as are all taxa of higher rank based on it (Articles 18

and 32 of the current Code).

Nymania capensis (Thunb.) Lindb. in Notiser ur

Sallskapets pro Fauna et Flora Fennica Forhand-

lingar 9: 290 (1868). Type: South Africa, Thunberg

s.n. (UPS, holo.).

Aitonia capensis Thunb.: 166 (1781).

Distribution and Ecology

Nymania capensis is widely distributed within the

Karoo-Namib floristic region of the Unesco/AET-

FAT/UNSO Vegetation Map of Africa (White

1983a). It occupies two main areas separated by an

interval of about 300 km.

In the north it extends southwards from Nauchas

and Rehoboth in SWA/Namibia to near the mouth

of the Orange River and from there inland to be-

yond the confluence of the Vaal and Orange Rivers.

In the south it occurs in the Little Karoo and in simi-

lar and related vegetation further east.

Most of the localities from which N. capensis has

been collected are located within mapping unit 51,

Bushy Karoo-Namib shrubland, of White (1983a),

which in South Africa consists largely of Acocks’s

(1975) three types of karroid broken veld, namely:

No. 26, Karroid Broken Veld sens, strict . ; No. 32,

Orange River Broken Veld; No. 33, Namaqualand

Bothalia 16,2 (1986)

147

Broken Veld, although N. capensis appears to be

confined to the northern end of this.

North of the valley of the Orange River, N. capen-

sis extends into the region of the southern Kalahari

Sands (mapping unit 16, Kalahari Thornveld and

Shrub Bushveld of Acocks, towards the southern

limit of phytochorion XIV, the Kalahari-Highveld

Regional Transition Zone of White). Here it occurs

in bushland on the Langeberg and the Asbestos Mts

and on the Kaap and Ghaap plateaux. On the lower

slopes of the latter it is occasional all the way from

Vryburg to Griquatown (A. A. Gubb in litt. 15 Feb.

1985). It also occurs on quite low, small and isolated,

rocky outcrops emerging from a sea of red Kalahari

Sand which extends for miles around, as in the vicin-

ity of Pearson’s Hunt, (2722 CC, Gubb s.n.).

In the south of its range, to the east of the Little

Karoo N. capensis is mainly confined to dry areas in

valleys and depressions in the rain shadow of moun-

tain ranges, as far east as the Great Fish River be-

tween Carlisle Bridge and Komadagga (Mullins s.n.,

3326 AA). Some of these localities are inside the

Tongaland-Pondoland Region (White 1983a) but

near its extreme south-eastern limit.

Information on the vegetation types in which N.

capensis occurs is given by Acocks (1975: 42, bush-

land on rocky soil in Veld Type 16, Kalahari Thorn-

veld; 58, Veld Type 24, Noorsveld; 59, Veld Type

25, Spekboomveld; 61, Veld Type 26, Karroid Bro-

ken Veld of the Little Karoo; 72, Veld Type 32,

Orange River Broken Veld; 75, Veld Type 33, Na-

maqualand Broken Veld), and by Van der Walt

(1968), Noorsveld.

Figure 1 shows the overall distribution of N. ca-

pensis as revealed by herbarium specimens. A circle

has been placed in the middle of each quarter degree

square from which it is known to have been col-

lected. In the north-western Cape, however, it is

much more extensive than herbarium specimens in-

dicate. Site records in the area based on an outline

distribution map and additional information sup-

plied by A. A. Gubb are shown by stars.

Figure 2 shows that although N. capensis is wide-

spread in the Cape Floristic Region it is absent from

typical Cape vegetation and only occurs in enclaves

of karroid types.

Pollination

According to Vogel (1954) birds visit the flowers,

which, in the shape, size and colour of the corolla

and in the structure of the androecium and copious

nectar production, are typically ornithophilous.

Fruit type and seed dispersal

The fruits are large, loculicidal, papery capsules,

up to 40 mm in diameter. They are deeply lobed with

4 laterally compressed, wing-like expansions. They

are conspicuous and usually persist on the plant for

several months. At first they are suffused with car-

mine, but later become straw-coloured and even-

tually silvery grey. The capsules are dehiscent only

near the apex. Of the 8 ovules in the ovary, rarely

more than 4 develop into seeds. In some herbarium

specimens the seeds have fallen away from the pla-

centa but in others they remain firmly attached.

The seeds are very distinctive. They are a dull

dark brown and kidney-shaped, with a thick, rather

woody, minutely puberulent testa. There is no aril,

but in the ovule an adaxial concavity is filled by a

fleshy outer layer of the testa which disintegrates be-

fore the seed is mature (Pennington & Styles 1975:

462). This leaves a deep chamber with a small en-

trance hole. The embryo is strongly curved and em-

bedded in thin endosperm. The seeds appear to be

much lighter than Turraea seeds of comparable size.

Little has been published on dispersal. Palmer &

Pitman (1972: 1059) state that the capsules are dis-

persed by wind.

FIGURE 1. — Distribution of Ny-

mania capensis in relation

to the regional phytochoria

of the Unesco/AETFAT/

UNSO Vegetation Map of

Africa (White 1983a). One

symbol is shown for each

quarter degree square. Cir-

cles represent herbarium

specimens: stars, sight re-

cords (see text). II, Zambe-

zian regional centre of

endemism: V, Cape re-

gional centre of endemism

(enclaves of Karoo and Af-

romontane vegetation not

shown); VI, Karoo-Namib

regional centre of ende-

mism: VIII. Afromontane

archipelago-like regional

centre of endemism: XIX7.

Kalahari-Flighveld regional

transition zone; XV. Ton-

galand-Pondoland regional

mosaic.

148

Bothalia 16,2 (1986)

18° 20° 22° 24° 26°

FIGURE 2. — Distribution of Nymania capensis in the southern part of its range in relation to the Cape Floristic Region as circum-

scribed by Goldblatt (1978) and Bond & Goldblatt (1984). Stipple represents fynbos and related types (Acocks’s mapping

units 43, 46, 47, 69, 70) which according to some workers (e.g. Taylor 1978; White 1983a) comprise the Cape Region sensu

stricto. Black represents forest. Within Goldblatt's boundary, areas left white signify enclaves of Karoo vegetation (Acocks’s

mapping units 23, 25, 26, 31, 34), and valley bushland (Acocks’s mapping unit 23) of Tongaland-Pondoland affinity.

1, Gamtoos River bushland; 2, Klein Brak River bushland; 3, Gouritz River bushland. Only selected localities (stars) of

Nymania capensis are shown — sufficient to indicate its geographical range. I know of no records from characteristic Cape

vegetation.

According to A. Gubb (in litt. 26 April and 28

May 1985) the fruits remain on the plant until the

end of winter, i.e. August, which is the windy time

of year. They are knocked off by the shaking of the

shrub by wind action and by buffeting of the sur-

rounding branchlets, whereupon they roll away

across the ground with the wind. In the course of this

movement the parchment-like capsule cracks open

in many places and the seeds are released and pre-

sumably germinate with the spring rains in mid-Oc-

tober to late November. It is not known whether

under exceptionally windy conditions the fruits or

seeds ever become air-borne and are thereby trans-

ported for greater distances. The bright red capsules

are conspicuous, but there is no evidence that this

attracts potential dispersers.

Leaf fall

During the winter months the leaves become

harder and begin to lose colour and by the end of

winter up to 60% or more may have fallen. In spring

new leaves appear and the remaining old leaves are

shed. The plants are not truly evergreen since all the

leaves are replaced each year and they are active for

only about 9 months. Nor is the species truly decidu-

ous since on all individuals at least some leaves are

retained throughout the winter. Many other species

in the northern Cape behave in a similar manner (A.

Gubb in litt. 28 May 1985).

The occurrence of Nymania capensis in Ovambo-

land

This species is included in Rodin’s posthumously

published (1985: 113), fascinating and beautifully il-

lustrated book on the ethnobotany of the Kwanyama

Ovambos who live in the extreme north of SWA/Na-

mibia. Rodin found one 10 m high tree with a

gnarled trunk 1 m in diameter close to St Mary’s

Mission at Odibo. This is 650 km north of its nearest

known locality. Rodin says that his plant has the

same Kwanyama name (omunghudi) and the same

use as Boscia albitrunca (Capparidaceae), and that

this coincidence should be checked further. One of

the specimens he cites ( Rodin 2665, sterile, PRE),

although atypical in some respects, is quite a good

match for B. albitrunca, and the occurrence of Ny-

mania in Ovamboland thus seems unlikely.

2. TURRAEA L.

Sectio Turraea

Shrubs or trees. Flowers usually in sessile or pe-

dunculate fascicles. Bracteoles inserted at base of the

pedicels. Calyx lobes rarely foliaceous, united in

lower half. Style-head distinctly wider than the style,

capitate, with a single, terminal stigmatic surface,

distinctly exserted beyond the anthers. Capsule usu-

ally more than 10 mm in diameter. Seeds usually

mofe than 5 mm long; aril usually red or orange and

Bothalia 16,2 (1986)

J49

covering more than one-tenth of the surface of the

seed.

1. Turraea nilotica Kotschy & Peyr., Plantae

Tinneanae: 12, fig. 6 (1867).

Distribution, ecology and relationships

T. nilotica extends from the Sudan and Ethiopia

southwards to the Transvaal. Since it occurs in six

regional phytochoria it is a transgressor and can be

referred to as an ‘eastern wide’. It has corky, fire-re-

sistant bark and frequently occurs in savanna wood-

land. It is closely related to T. zambesica (q.v.) and

T. robusta Giirke which is found on the African

mountains from Uganda and eastern Zaire to Ma-

lawi.

Capsule structure and seed dispersal

The fruit is a small, 10-valved, leathery capsule

which becomes thinly woody after opening. Dehis-

cence is similar to that of T. obtusifolia. The seeds,

however, which are 5x3 mm, have black testas and

are superposed if both ovules in a locule develop to

maturity. The small aril is said to be orange or red-

dish and in herbarium specimens appears to be al-

most completely concealed. The coloured illustra-

tion in Coates Palgrave (1956: 232) shows black

seeds attached to a massive red central column; to

judge from preserved material the size and nature of

this column is not shown accurately. Field obser-

vations are needed. It seems that the septa remain

membranous and that the small orange aril is largely

confined to the adaxial surface of the seed except for

a horn-like extension which protrudes beyond its

apex. Nothing definite is known about dispersal.

Rodgers (1976), who examined the rumen contents

of 29 mature impala ( Aepyceros melampus ) from

south-east Tanzania, found that fruits of T. nilotica

were frequently present.

2. Turraea zambesica Sprague & Hutchinson ex

Styles & F. White in Boletim da Sociedade Brote-

riana, ser. 2, 36: 71, fig. 1 (1962).

This species is only known from a small part of the

Zambezian Region. It is confined to the Zambezi

Valley and its tributaries. Its range lies partly within

that of T. nilotica but at lower altitudes. It also ex-

tends further to the west. It would be interesting to

compare these species in the field.

3. Turraea obtusifolia Hochstetter in Flora 27:

296 (1844).

Distribution, ecology and relationships

T. obtusifolia is widely distributed in southern

Africa from Zimbabwe to the eastern Cape (Figure

3). It occurs throughout the greater part of the Ton-

galand-Pondoland floristic region (White 1983a)

with a short penetration into the southern part of the

Zambezian Region. It is a southern vicariad of the

tropical species T. mombassana Hiern ex C. DC.,

which extends from Ethiopia to Malawi. The differ-

ences between them are given by White & Styles

(1963).

Variation and taxonomy

The shape and size of the leaves are extremely

variable. Variation in southern Africa is summarized

in Figure 3, from which it can be seen that, although

there are some geographical trends, the latter are in-

sufficiently striking to serve the needs of formal tax-

onomy.

In general, plants with broad, rather deeply lobed

leaves tend to be concentrated towards the middle of

the range within about 200 km of Durban, the type

locality, although the type specimen itself has rela-

tively narrow, scarcely lobed leaves. In the past the

name T. obtusifolia has been most frequently ap-

plied to the broad-leaved variants.

Towards the north and the south of the species

range, variants with narrower, slightly lobed or un-

lobed leaves become frequent and locally predomi-

nate, though the broad-leaved variant occurs, at

least sporadically, throughout the greater part of the

area occupied by the species.

A narrow-leaved specimen from the extreme

south was described by Casimir de Candolle (1878:

440) as T. obtusifolia var. microphylla and that name

was subsequently applied to similar variants from

the Transvaal (Burtt Davy 1932), though Breme-

kamp (1933) gave the latter specific rank as T. ob-

lancifolia. A detailed study of all the available, and

by now copious, material has failed to reveal any dis-

continuities on which more than one taxon could be

based.

To facilitate comparison, in Figure 3, variation in

leaf shape has been assigned to two categories,

namely (a) relatively narrow, unlobed or slightly

lobed leaves and (b) broader, shallowly to deeply

lobed leaves. Their distribution, based on all avail-

able material in the National Herbarium, Pretoria is

as follows:

(1) Botswana and Transvaal: a, 67 specimens

(93%); b, 5 specimens (7%).

(2) Swaziland and Natal south to Durban: a, 12

specimens (32%); b, 26 specimens (68%).

(3) Natal south of Durban, Transkei, eastern

Cape: a, 24 specimens (70%); b, 10 specimens

(30%).

Both variants also occur in the remainder of the

species range outside southern Africa, namely in

Zimbabwe and southern Mozambique. The leaves of

T. obtusifolia are often variable on a single plant

(Figure 3a) and their precise outline seems to de-

pend, at least in part, on local conditions. Large,

deeply lobed leaves occur most frequently inside the

forest (e.g. Ross & Moll 2309 from Hawaan).

Bremekamp suggested that T. oblancifolia also

differs from T. obtusifolia in its depressed-globose

not cylindrical style-head (‘stigma’) and in having

longer, broader calyx-lobes which are not separated

from each other by a wide sinus. As with leaf-shape,

there seem to be broad geographical trends in these

features but they are too imprecise to be taxonomi-

cally useful.

150

Bothalia 16,2 (1986)

FIGURE 3. — Turraea obtusifolia. Pictorialized distribution map showing variation in southern Africa of shape and size of leaves.

The specimens are numbered consecutively from north to south and the degree square from which each specimen was col-

lected is indicated on the map. A, Smith 3636 from East London showing variation in leaf shape on a single twig; 1, Van der

Schijff 3802 ; 2, Ihlenfeldt 2253 ; 3, Van der Schijff & Marais 3671; 4, Fourie 2627; 5, Mogg 24436; 6, Hansen 3296; 7, Barnard

387; 8, Thode A 1368; 9, Codd 722; 10, De Winter 8635; 11, Van Vuuren451; 12, Du Toit 189; 13, Pooley 384; 14, Reid 496;

15, Ward 4387; 16, Wells & Edwards 77; 17, Mthonti 1; 18, Ward 1844; 19, Moll 3110; 20, Ross & Moll 2309; 21, Wood 5746;

22, Krauss 308 from Port Natal (Type of T. obtusifolia); 23, Strey 8065; 24, Wylie s.n. ; 25, Venter 1035; 26, De Winter 8861 ;

27, Comins 1046; 28, Pegler 337; 29, Tyson s.n. (Kowie); 30, Tyson s.n. (Port Alfred); 31, Jacot Guillarmod s.n.

Bothalia 16,2 (1986)

151

Floral structure and pollination

The flowers are similar to those of T. floribunda

but the proportions are slightly different. The petals

are pure white and the style-head is cylindric. The

following observations were made in Zimbabwe (F.

White, MS 1973). The flowers seem to last more

than one night. By 10h30 they are no longer fragrant

and some had withered. Some which were still fresh

appeared to have been visited by moths the previous

night, since the style had been pushed to one side

and the pollen had been removed from the recepta-

culum pollinis on the side of the flower where the

proboscis had entered the staminal tube. In some

fresh but unvisited flowers, the style remained cen-

trally placed and pollen occurred all the way round

the receptaculum pollinis. In the open flower the

anthers and appendages are disposed horizontally

and it is unlikely that they would come into contact

with the proboscis of a visiting hawk moth.

Capsule structure and seed dispersal

The fruit is a small, 5-valved, leathery loculicidal

capsule which becomes woody after dehiscence. The

rather thin valves and outer parts of the septa separ-

ate from the inner parts of the septa and the central

placental axis, to which the 6-10 seeds remain firmly

attached. The seeds, which are 5,5 mm long and

have a bright red, shining testa, are tightly packed

together, and are very conspicuous against the pale

straw-coloured inner surface of the now horizontal

or reflexed lobes of the capsule.

The white aril is very small and is completely hid-

den unless the seed is removed. It consists of two

thin fleshy wings which are free except for a narrow

attachment along the raphe. It covers less than one

sixth of the surface of the seed and scarcely extends

beyond the margins of the adaxial cavity.

The seeds of T. obtusifolia appear to mimic the

more conspicuously arillate seeds of other plants,

and it is possible that fruit-eating birds are deceived

by their appearance and play some part in their dis-

persal without obtaining much nourishment from

them. It is also possible that ants eat the arils of

fallen seeds and play a local role in dispersal, as they

are said to do (Milewski & Bond 1982) in the case of

some other South African plants with small arils

(e.g. Pterocelastrus).

Attractive and informative coloured photographs

of the fruits of T. obtusifolia have been published by

Onderstall (1984, opp. p. 122 and a newspaper cut-

ting in PRE).

4. Turraea floribunda Hochstetter in Flora 27:

297 (1844).

Distribution and ecology

T. floribunda is an ‘eastern wide’ which extends in

various types of forest from the Sudan and eastern

Zaire to southern Africa. In tropical Africa its distri-

bution is mostly scattered.

Floral structure and pollination

The flowers open at night and are visited by hawk

moths which arrive en masse at the trees at dusk.

They stay for 15-30 minutes and then leave together

(T.K. Lowrey in lift. 21 June 1985). Further informa-

tion is not available. It would seem that the elon-

gate, divergent, greenish white petals act as a distant

visual attractant and that the much smaller radiating

staminal appendages enable the pollinator to focus

more precisely on the extremely narrow entrance to

the staminal tube. The anthers dehisce before the

flower opens and pollen grains may be seen adhering

to the emerging discoid style-head which appears to

function as a receptaculum pollinis (F. White, pers.

obs.). At this stage the apical stigmatic surface,

which is less than half the diameter of the style-head,

is free from pollen grains. In the mature flower the

style-head is far-exserted and in some flowers the

style is bent through nearly 90 degrees near its apex,

and possibly thereby places the stigma in a suitable

position for the reception of pollen. The stigma is

minute, especially in relation to the size of the flower

and its pollinators. It would be interesting to know

precisely how pollen transfer is brought about.

Style length varies in different parts of the geo-

graphical range of T. floribunda. In southern Africa

it is usually less than 40 mm long whereas in east

Africa it can reach 100 mm. It would be worth inves-

tigating the significance of this in relation to its polli-

nators.

Capsule structure and seed dispersal

The fruit is a 10-valved leathery capsule with very

thick (4—6 mm) valves which, after dehiscence, be-

come woody and divergent like the rays of a starfish;

ultimately they are sometimes reflexed. Dehiscence

is similar to T. obtusifolia but relatively few seeds

mature, normally only 5-6 out of a possible 20. The

seeds have an orange testa which contrasts with the

whitish fleshy aril. The latter covers approximately

one third of the seed, and its margins are visible

flanking the seed. The seeds, which are sometimes

superposed, are small in relation to the size of the

capsule and are individually rather than collectively

conspicuous. Nothing is known about their dis-

persal.

Sectio Nurmonia (Harms) F. White , comb, et stat.

nov.

Nurmonia Harms in Berichte der Deutschen bo-

tanischen Gesellschaft 35: 74—82 (1917a). Type

species: Turraea pulchella (Harms) Pennington in

Pennington & Styles (1975).

Suffrutices. Flowers solitary or in 2-3-flowered

cymes. Bracteoles inserted on the pedicels. Calyx

lobes foliaceous, free almost to the base. Style-head

only slightly wider than the style, with 5 stigmatic

lobes at apex, not or only slightly exserted. Capsule

up to 8 mm in diameter. Seeds c. 3 mm long; aril

whitish and inconspicuous, covering about one tenth

of the surface of the seed.

5. Turraea pulchella (Harms) Pennington in

Blumea 22: 454, fig. 3d (1975). Type: Transkei: near

Kentani, rare, 330 m, fl. March 1903, Pegler 730 (B.

holo. t?). Several other specimens with the same

number were also collected by Pegler near Kentani.

but on different dates between April 1900 and Oc-

152

Bothalia 16,2 (1986)

FIGURE 4. — 1, Turraea pul-

chella, habit x 0,4; la,

flower in longitudinal sec-

tion, x 5,7; lb, sepal, x

5,7; lc, petal, x 5,7; Id,

part of staminal tube and

anthers, x 5,7; le, fruit and

leaves, x 0,4; If, fruit x

1,4 (all from Pegler 730). 2,

Turraea streyi, habit, x 0,4;

2a, flower, in longitudinal

section, x 2,8; 2b, anthers

and appendages, x 5,7; 2c,

fruiting branchlet, x 0,4;

2d, fruit, x 1,4; (all from

Strey 6878).

tober 1913; among them the following is selected as

neotype: Transkei, Kentani District, 305 m occa-

sional, valley, bank of stream, rare, fl. , frt. March

1903, Pegler 730 (K, neo.!, here designated, BOL!).

The neotype may be a duplicate of the holotype but

the matter is by no means certain.

Nurmonia pulchella Harms: 80, fig. 1 (1917).

Turraea heterophylla sensu Pegler: 12 (1918).

Distribution , typification and ecology

Only known from Kentani District in Transkei

where it was collected by Miss Alice Pegler several

times between Apr. 1900 and Oct. 1913. Miss Pegler

gave the same number to all her gatherings which

were distributed to several herbaria. In addition to

the neotype I have seen the following:

TRANSKEI. — 3228 (Kentani Distr . ) : valleys 610 m, fl.-buds

Apr. 1900, Pegler 730 (PRE!); occasional, fl. Mar. 1902, Pegler

730 (SAM!); 305 m, fl., frt. Apr. 1903, Pegler 730 (SAM!); 305 m.

occasional, fl., frt. 15 Oct. 1904, Pegler 730 (PRE!, SAM!); 305

m, hill slopes, occasional, fl., frt. 10 November 1905, Pegler 730

(FHO!); 365 m. along valleys, fl. Oct. 1911. Pegler 730 (PRE!);

365 m, thick, woody underground stem, fl., imm. frt. 15 Oct.

1913, Pegler 730 (PRE!); 365 m, about 6-10 in. above ground, fl.

Oct., Pegler 730 (K!) No information given: frt., Pegler s.n. (PRE

ex Herb. Marloth!); fl., frt., Pegler 730 (P!).

T. pulchella , it seems, has a very restricted distri-

bution and has not been collected for more than 70

years. Miss Pegler did not give precise details on her

labels, but according to Gunn & Codd (1981) most

of her specimens were collected from within 13 km

of Kentani Village. They appear to have come from

various localities between 305 and 610 m. The only

ecological information she provided (Pegler 1918) is

that it grows among tall grass. Herbarium specimens

suggest that T. pulchella can tolerate, and may pos-

sibly be adapted to, at least light, fires. On the her-

barium specimens all the shoots that bear leaves be-

long to the current year’s growth. They arise from

short, branched, older, woody stems, some of which

look as if they might have been burnt back in pre-

vious years (Figure 4.1). In its manner of growth T.

pulchella resembles the geoxylic suffrutices de-

scribed from tropical Africa by White (1976).

Bothalia 16,2 (1986)

153

According to Pegler (1918) fires in Kentani District

had greatly increased during iier life-time and had

led to an impoverishment of the flora. This species

must surely qualify for inclusion in future editions of

Threatened plants of southern Africa’ (Hall et al.

1980).

Floral structure and pollination

Interpretation of herbarium specimens is difficult

but it is possible that there is a primitive receptacu-

lum pollinis mechanism. In one flower which was

dissected an anther was found to be firmly attached

to the style-head.

Capsule dehiscence and seed dispersal

The small capsules and seeds are likely to be in-

conspicuous to birds, especially as the plant is said to

grow among tall grass. In herbarium specimens, in

capsules beginning to dehisce, the seeds readily be-

come detached from the placenta. In the field, when

they fall to the ground, it is possible that they are

dispersed by ants. Occasional dispersal by small

seed-eating birds cannot be ruled out. The extremely

restricted distribution of T. pulchella suggests that

dispersal, whatever the means, is not very efficient.

6. Turraea streyi F. White & B.T. Styles, sp.

nov.

Species nova inter species Africanas solum prope

T. pulchellam (Harms) Pennington ob habitum suf-

fruticosum, lobos calycis foliaceos, stylum brevem,

semina minuta et capsulam quinquevalvem po-

nenda; ab omnibus speciebus generis foliis composi-

te differt.

TYPE. — Natal, 3030 (Port Shepstone): St Mi-

chael's-on-Sea, Deppe's Farm (-CD), a heavily

browsed 'bush' in bushveld, white flowers, fl. 19

Sept. 1966, Strey 6876 (PRE, Sheet 1 holo.!; NH!,

NU, 2 sheets!).

Among African species only to be placed close to

T. pulchella (Harms) Pennington on account of its

suffruticose habit, foliaceous calyx-lobes, short

style, minute seeds and 5-valved capsule; differs

from all species in the genus in its compound leaves.

Suffrutex up to 0,75 m high; branchlets, inflores-

cence-axes and both leaf surfaces sparsely to densely

setulose. Leaves up to 70 mm long, very variable,

trifoliolate, twice-trifoliolate or imparipinnate with

3-5 deeply lobed or trifoliolate divisions; lobes

rounded to acute. Flowers axillary, solitary or in lax

2-3-flowered cymules; pedicel or peduncle slender,

up to 35 mm long, bracteoles minute, filiform, ± 1

mm long. Calyx 3-5 mm long, hispidulous, lobes fo-

liaceous, oblong-elliptic, acute, free almost to the

base. Petals white, glabrous, 8-11 x 3-4 mm,

broadly spathulate. Staminal tube 7-9 mm long,

hairy in upper half inside, not split at apex; append-

ages paired, filiform, alternating with and much

longer than the anthers; anthers long-apiculate, de-

hiscing by very short slits in lower half. Ovary

densely hairy, 5-locular with 2 collateral ovules per

locule; style 7-10 mm long, included or very slightly

exserted, hairy in lower half; style-head capitate,

less than 1 mm in diameter with a terminal, 5-lobed,

coroniform stigma. Capsule 5x8 mm, up to 10-

seeded, otherwise as in T. pulchella. Chromosome

number-. 2n = 36 {Strey 9288 South Africa). Figure

4.2.

T. streyi is named in honour of its discoverer, Ru-

dolf Georg Strey, distinguished contributor to South

African botany who guided the senior author of this

species through parts of Natal, the Transkei and the

eastern Cape in 1973.

NATAL. — 2931 (Stangcr): King Hamlyn’s Farm (-AD).

scrub forest, small sub-woody plant in the lower storey, 0,25 m, fl.

19 Sept. 1971, Molt 5502 (PRE). 3030 (Port Shepstone): Deppe's

Farm (-CD), next to ‘Skyline’, St Michael’s-on-Sea, erect ‘herb'

in heavily grazed grassland, up to 0.4 m high where protected:

flowers white; locally fairly common, fl., frt. 10 December 1968,

Ross 1853 (FHO!, NH!, PRE!); Uvongo road, bush margins; fl.,

frt. 27 Nov. 1969, Strey 9288 (NH, 3 sheets!).

Distribution and ecology

T. streyi is only known from two widely separated

localities in the Tongaland-Pondoland phytogeogra-

phical region of the Unesco/AETFAT/UNSO ‘Ve-

getation map of Africa’ (White 1983a).

It occurs both inside and at the edges of scrub for-

est and bushland, and in both rank and heavily

grazed grassland. At the type locality (White, MS

1973) the vegetation is a mosaic of grassland and

open bushland in which Strelitzia nicolai Regel &

Koern.. Dalbergia obovata E. Mey., Chaetacme aris-

tata Planch., Acacia karroo Hayne. Psidium guajava

L., Rhus chirindensis Bak. f., Ekebergia pterophylla

(C. DC.) Hofmeyer, Loxostylis alata Spreng. f. ex

Reichb. and Zanthoxylum capense (Thunb.) Harv.

are conspicuous.

Its growth form varies according to local ecologi-

cal conditions. In the shady undergrowth of forest

{Moll 5502 ) the stems are slender and the leaves 3-

foliolate and shallowly lobed. In rank grassland the

stems are elongate and only sparsely branched.

When it is heavily browsed ( Strey 6876) it is richly

branched and shrubby at the base. Nothing is known

about its response to fire, but some specimens (e.g.

Strey 6288) look as if the previous year's growth had

been singed and killed back by fire. In its habit, T.

streyi is similar to a composite, Schistostephium hep-

talobum (DC.) Oliv. & Hiern, which grows with it,

and mixed gatherings have been made. Sheet 2 of

Ross 1853 (FHO) is Schistostephium.

Floral structure and pollination

The flowers are similar in structure to those of

more typical species of Turraea except for their

smaller size, proportionally broader petals and much

less well-differentiated style-head. They possibly

have a primitive type of receptaculum pollinis mech-

anism. In one unopened flower on a herbarium

specimen the anthers had already dehisced and some

grains were adhering to the style-head, though none

were found on the stigmatic crests. The anther-slits

are about the same length as the style-head but they

produce many more grains than can be accommo-

dated on its surface. Most of the grains were en-

tangled among the hairs between and just beneath

the anthers.

154

Bothalia 16,2 (1986)

Capsule dehiscence and seed dispersal

The capsules are remarkably similar to those of T.

pulchella and the seeds are possibly dispersed in a

similar way.

3. MELIA L.

A small genus of three species. Two are indige-

nous to Africa. M. bombolo Welw. occurs in rain

forest in Gabon, Congo, Zaire and Angola, whereas

M. volkensii Giirke is a conspicuous emergent tree

in deciduous bushland in parts of the Somalia-Masai

Region in east Africa. The third species, M. azeda-

rach L., as a wild plant occurs in the more seasonal

forests of the Far East from India to Australia (Mab-

berley 1984). It has been widely planted for timber

and especially for ornament throughout the tropics

and subtropics, including all the warmer parts of

southern Africa.

Melia azedarach L.

Two groups of variants of this species have been

widely planted in Africa: (a) The ‘Wild’ plant or

White Cedar is often grown for forestry purposes,

but no herbarium specimens have been seen from

southern Africa; (b) What Mabberley refers to as

the ‘Indian Cultivars’, which are widely known as

Persian Lilac and less often as Bead-tree.

In southern Africa, and to a lesser extent else-

where, the nomenclature of this plant, both popular

and scientific is confused. Linnaeus described two

species of Melia with very similar names, namely

Melia azedarach and M. azadirachta. The latter, the

Neem or Nim Tree, is now placed in a different

genus and is known as Azadirachta indica. Because

of the similarity of their names, the one is often mis-

taken for the other. For this reason, much of the in-

formation on medicinal and other uses given under

Melia azedarach by Watt & Breyer-Brandwijk

(1962) and by some other authors refers to Azadi-

rachta. Linnaeus’s two species are also stated to be

synonymous in a recent publication on South Afri-

can introduced trees (Von Breitenbach 1984). In the

latter work the name ‘Syringa’ is proposed as the Na-

tional Name for Melia azedarach. This is unfortu-

nate since Syringa is a well-known generic name in

Oleaceae and has also been used as a popular name

for species and cultivars of Philadelphus (Saxifraga-

ceae sensu Engler).

The following notes refer to typical Persian Lilac.

In addition, the cultivar ‘Umbraculifera’, the Texas

Umbrella Tree, a mutant form with a flattened

crown, is sometimes planted in gardens.

Distribution and ecology in southern Africa

M. azedarach has been planted in all the warmer

parts of southern Africa. It is widely naturalized and

locally has become a pest. As early as 1906 it was

established near Barberton (Burtt Davy 1932). In

the Kruger National Park it is liable to supplant the

natural vegetation in the river valleys and is difficult

and expensive to eradicate (Van Wyk 1984). It is

also invasive in Natal (W. R. Bainbridge pers.

comm.). According to Henderson & Musil (1984)

Melia azedarach is the most widespread and aggress-

ive of the invasive introduced trees in the Transvaal.

It is highly penetrative and is often found far from

buildings. It is drought- and frost-resistant and has

become a roadside weed and has invaded water-

courses and natural, but presumably disturbed, ve-

getation including bushland and forest. Henderson

& Musil suggest that the few remaining relict stands

of forest in the Transvaal are liable to be replaced by

exotics such as Melia azedarach, though this may be

somewhat exaggerated. They did not apparently

study dispersal of this species.

Fruit structure, toxicity, chemistry and dispersal

The fruit is a drupe. Until recently the most thor-

ough investigation of its properties was by Steyn &

Rindl (1929), who refer to the conflicting evidence

of earlier work. Some of the publications they cite

state that children can eat the fruit without incon-

venience whereas others mention fatal cases of pois-

oning. Steyn & Rindl found that none of their ex-

perimental animals would ingest the drupes which to

man have an unpleasant smell and an intensely bit-

ter, nauseating taste. It was necessary to force feed

them with extracts of ground-up fruits by means of a

stomach tube. Pigs, sheep, goats, rabbits and gui-

nea-pigs were found to be affected by Melia poison,

with pigs the most susceptible. For pigs the lethal

dose, however, was quite large, 150-200 grams of

drupes for an animal weighing 75 kilograms. By con-

trast, Muscovy ducks were not killed even by rela-

tively high doses. It was pointed out that different

kinds of wild birds are fond of the fruit but ingest

only the flesh and discard the kernels, and that the

locus of the toxins, flesh, kernel or both, was not

known at that time. Watt & Breyer-Brandwijk de-

vote several pages of uncritical and inconclusive dis-

cussion to the toxicity or otherwise of the Melia fruit,

from which it is difficult to draw any conclusions.

Oelrichs et al. (1983) have recently extracted and

identified four meliatoxins (a group of limonoids)

from the flesh of Melia azedarach and confirmed its

highly toxic nature. Their experimental pigs showed

rapid muscular contractions within 2-4 hours of

drenching, followed by collapse, rapid heart beat

and dilated pupils. Death occurred after about 30

hours. The meliatoxins are believed to have been re-

sponsible for the acute nervous symptoms and rapid

death in pigs, though other compounds in the fruit

are thought to have other adverse effects. Oelrichs et

al. obtained their material from five localities in

Queensland, where the tree is native. The concen-

tration of meliatoxins in the fruit was variable and in

three cases they were absent. The extent to which

this variability may depend on the degree of ripeness

of the fruit is not clear and requires further investiga-

tion. One of the meliatoxins extracted from Melia

azedarach is very similar structurally to an insect an-

tifeedant, trichilin A, which occurs in Trichilia eme-

tica (‘roka’; Nakatani et al. 1981). The limonoids in

the flesh of the fruit are different from those of the

seed (D. A. H. Taylor pers. comm.).

Recent work has shown that M. azedarach is very

variable chemically. It almost seems that no trees are

alike, though the overall pattern is constant enough.

Bothalia 16,2 (1986)

155

Kraus et al. (in press in Tetrahedron ; preprint sent to

D. A. H. Taylor, pers. comm.) have recently discov-

ered a set of limonoids in cultivated plants of M. aze-

darach from Greece which are different from those

that Oelrichs found. They have also confirmed that

azadirachtin occurs in both Melia and Azadirachta.

Only casual observations are available on the dis-

persal of Melia azedarach. In Australia, where it is

native, its fruits are eaten by the Topknot pigeon

(Lopholaimus antarcticus) in August and Septem-

ber, when its preferred fruits (species of Lauraceae

and Palmae) are scarce (Frith 1957). They are not an

important item in the diet of this species, although

they are said to form the principal winter food of the

Wompoo Pigeon (Ptilinopus magnificus). For south-

ern Africa, Rowan (1967) records that the fruits are

eaten by species of Mousebird (Colius) and the Grey

Loerie (Corythaioxoides concolor). If eaten too

freely they narcoticize the Loerie which has been

seen to fall from the tree in which it was feeding. A

similar reaction has not been seen to occur in the

Mousebird. In Natal, according to W. R. Bainbridge

(pers. comm.) M. azedarach is dispersed by fruit

bats. In Durban and Pietermaritzburg it is now un-

popular as a garden plant because the bats often

leave unsightly excrement stains on the walls of

buildings.

The dispersal biology of M. azedarach , both in its

native lands and elsewhere, it seems, is complex.

The principal function of the meliatoxins is probably

to protect the developing fruit from predators. It

would be interesting to know the extent to which

they are present in the fully ripe fruit and, if so, the

influence this has on dispersal.

4. AZADIRACHTA Adr. Juss.

Azadirachta indica Adr. Juss. *in Memoires de

Museum nationale d'histoire naturelle 19: 221

(1830).

The Neem Tree is a native of India and Burma. It

is widely planted in the drier parts of Africa for tim-

ber and ornament, but is not often seen in southern

Africa. For semi-arid regions, Radwanski & Wick-

ens (1981) advocate the use of Azadirachta indica in

an alternative approach to agricultural production

which relies on vegetative fallow for the recycling of

plant nutrients and is closely linked with rural indus-

try based on plant products. The whole plant is med-

icinal. One of the most powerful naturally occurring

insect antifeedants, the limonoid azadirachtin, oc-

curs in this species. It can be used to control various

types of insect larvae including locusts. At concen-

trations as low as a few parts per million it is active

against larvae of Lepidoptera (Zanno et al. 1975).

Azadirachtin acts by appetite suppression and even-

tually the larvae die of starvation. It also inhibits ec-

dysis and so kills insects. It is especially active

against the tobacco budworm, which is a serious

pest, and is being used in field test (D. A. H. Taylor

pers. comm.). Its molecule is too complicated for

economic synthesis, but the use of crude extracts of

* The precise date of publication is uncertain (see Stafleu &

Cowan, Taxonomic literature , edn 2, vol. 2: 476, 1979).

limonoids from the Neem Tree and other Meliaceae

including Melia azedarach is being investigated (Pic-

kett 1985). The fruit pulp of Azadirachta apparently

has not yet been analysed (D. A. H. Taylor pers.

comm.) and it is not known whether it is toxic. In

Ghana the fruits are extensively distributed by fruit

bats (Ayensu 1974). Viable seeds have also been ob-

tained from the dung of baboons (Lieberman et al.

1979).

5. EKEBERGIA Sparrm.

1. Ekebergia capensis Sparrm. in Svenska

vetenskapsakademiens handlingar 40: 282, fig. 9

(1779); White & Styles: 316, fig. 62 (1963) Styles:

409 (1974); Styles & White, Meliaceae in Flora of

Ethiopia (in press).

E. senegalensis Adr. Juss.: 234, 273 (1830); Exell & Mendonqa:

316 (1951); Keay: 705 (1958); Staner & Gilbert: 208 (1958);

Styles: 410 (1974), synon. nov.

E. mildbraedii Harms: 229 (1917b); Staner & Gilbert: 210, fig.

23 (1958), synon. nov.

Distribution, ecology and taxonomy

E. capensis is widespread on the African mainland

extending from Senegal eastwards to Ethiopia and

from there southwards, mostly in montane and ripa-

rian forest, to the forests of the southern Cape.

There is also a westward extension into Shaba, Zam-

bia, Zimbabwe and Botswana and outlying popula-

tions occur in Angola. It is absent from most of the

lowland rain forests of the Guineo-Congolian Re-

gion, but occurs locally towards their northern

fringes and extremely rarely in their interior as at

Yangambi in the heart of the Zaire basin. Through-

out most of its range E. capensis is a forest species,

but in places, from west Africa to Uganda, it can be

found in savanna woodland. Because it occurs in

more than one major vegetation type and more than

one regional phytochorion, it is an ecological and

chorological transgressor (White 1978a: 475; 1978b).

In common with many other widespread species, E.

capensis is very variable morphologically. The pat-

tern, however, is poorly correlated with ecology and

geography and it would be difficult to justify the re-

cognition of more than one taxon.

Variation in southern Africa

Variation in leaflet shape and size (and some

other features) in southern Africa is summarized in

Figure 5. In leaflet shape, most specimens from

southern Africa closely resemble E. capensis from

the mountains of east Africa as far north as Ethio-

pia, though some have smaller or relatively narrower

leaflets. A few specimens, e.g. Renny 121 from Le-

taba, Transvaal, have a densely tomentose lower

leaflet surface. Similar variants occur sporadically

elsewhere, and in Malawi were formerly given speci-

fic rank as E. buchananii Harms (see White & Styles

1963.)

In southern Africa the most distinctive variant oc-

curs towards the southern extremity of the range of

the species in the Transkei and Cape Province south-

eastwards from Kentani. These plants, e.g. Albany

Museum No. 25979, are characterized by slow-grow-

156

Bothalia 16,2 (1986)

FIGURE 5. — Ekebergia capensis. Pictorialized distribution map showing variation in southern Africa of: leaflet-shape and -size,

leaf-rhachis, and leaf-scars on branchlets. Specimens are numbered consecutively from north to south. For leaflets No. 3-14,

the number is also shown on the map inside the degree square from which the specimen it came from was collected. 1, Bos

9720; 2, Smith 1471 from Dikgathong, SE 1922; 3, Van Greuning 502; 4, De Souza 81; 5, Moll 4927; 6, Moll 1724; 7, Ward

5848; 8, White 10527; 9, Strey 10123; 10, Flanagan 818; 11, Pegler 849; 12, and 12a, Transvaal Museum; 13, and 13a Olivier

1101; 14, Marloth 7433. Leaflets and branchlets, x 0,6; leaf-rhachis, x 2,4. A, Devenish 1039 from N Natal showing remarkable

similarity to the Cape variants. Drawn by Gillian Condy.

Bothalia 16,2 (1986)

157

ing shoots with very prominent leaf scars (Figure 5.

12a), short leaves with small closely spaced leaflets

and a distinctly winged rhachis (Figure 5.13a), and

short inflorescences. Both the Cape and the north-

ern variants are sometimes grown for ornament, as

in Pretoria, and those who have been able to com-

pare them as living plants sometimes express sur-

prise that they should be regarded as conspecific. As

Figure 5 clearly shows, the overall pattern is too dif-

fuse to permit taxonomic subdivision. The popula-

tions between Port Shepstone and Kentani are inter-

mediate, and some populations south of Kentani,

especially those in the more luxuriant forests of

Alexandria and Knysna (e.g. Marloth 7433), more

closely resemble the northern plant. Furthermore,

specimens collected at high altitudes from several

localities in the north resemble the Cape variants in

some features. They include: Devenish 1039 from

Donkerhoek, Natal (Figure 5.A,Aa); Torre & Paiva

12731 from Serra Zuira, Mozambique and Paulo

1004 from Murua Nysigar Peak, Kenya.

2. Ekebergia pterophylla (C. DC.) Hofmeyr in

Journal of Botany, British and Foreign 63: 57

(1925).

Trichilia pterophylla C. DC.: 581 (1894).

Trichilia alata N. E. Br.: 160 (1896). In the protologue the fol-

lowing types are cited: Natal, Umhloti, Wood 1022 (K!) and

Groenberg, Wood 1043 (BOL!, Kl, PRE!, SAM!) and near Pine-

town, Wood 3403 (K!), 5439 (K!); Transvaal, near Barberton,

Galpin 1226 (BOL!, K!) and at Upper Moodies, Galpin 1083

(BOL!, K!, PRE!, SAM!). Of these, the Kew specimen of Wood

1043 has been labelled as the ‘type’ by N. E. Brown and is here

designated as a lectotype.

Distribution and ecology

E. pterophylla is a Tongaland-Pondoland near-en-

demic species. It is almost confined to the Tonga-

land-Pondoland regional mosaic but also intrudes a

short way into the south-eastern extremity of the

Zambezian Region (White 1983a & b). It occurs in

evergreen and semi-evergreen bushland and scrub

forest, especially in rocky places. Towards the north-

ern end of its range, as at Blyde Canyon Nature Re-

serve (Transvaal, 2430), its associates include typical

Zambezian species such as Combretum apiculatum

Sond., C. molle R. Br. ex G. Don, C. zeyheri Sond.,

Lannea discolor (Sond.) Engl, and Pterocarpus an-

golensis DC. Near its southern limit, as at the Um-

zimkulu Gorge (Natal, 3030) and other localities

nearby, the Zambezian element is almost totally

lacking and Tongaland-Pondoland endemic species,

such as Anastrabe integerrima E. Mey. ex Benth.,

Burchellia bubalina (L.f.) Sims, Diospyros simii

(Kuntze) De Winter, Loxostylis alata Spreng. f. ex

Reichb., Protorhus longifolia (Bernh.) Engl, and

Rhynchocalyx lawsonioides Oliv. occur with it

(White, MS 1973).

6. TRICHILIA P. Br.

The correct name for Trichilia emetica Vahl

The earliest published binomial for this plant ap-

pears to be Elcaja roka Forskal*. It is included in a

list of useful plants entitled Plantarum distributio

practica as a nomen nudum on page xcv of Fors-

kal’s Flora Aegyptiaco-arabica (1775). This work

was published posthumously by Carsten Niebuhr, a

mathematician and astronomer, who was the only

survivor of the ill-fated Danish Expedition to Arabia

Felix on which Forskal died (Hansen 1964). Nie-

buhr was not very well qualified to edit Forskal’s

work, which after publication was criticized by some

botanists for its inaccuracies. Although the generic

name Elcaja was validly published, the binomial E.

roka was not.

Fifteen years after the publication of Forskal’s

flora, the Danish botanist Martin Vahl (1790) at-

tempted to make good its deficiencies. He realized

that E. roka is a Trichilia, and described it as T. eme-

tica, citing Elcaja in synonymy. Vahl’s name was

used by all botanists until 1923 when Chiovenda

transferred E. roka to Trichilia in the mistaken be-

lief that it had been validly published, a view which

was endorsed by Brenan (1953). The name T. roka

was adopted in most floras during the next 10 years

(e.g. Keay 1958; Staner & Gilbert 1958; White

1962). It was also used in South Africa in some non-

botanical works dealing with poisonous plants (Watt

& Breyer-Brandwijk 1962) and garden trees and

shrubs (Van der Spuy 1971), and still persists spo-

radically in the phytochemical literature (Nakatani et

al. 1981).

After consulting the late J. E. Dandy, a leading

authority on nomenclature. White & Styles (1963)

reverted to the use of T. emetica, but did not publish

* This is the spelling which appears on the title page of Fors-

kal’s book. It has been very widely used, either in full or in an

abbreviated form, in taxonomic literature, including the Index

Kewensis, for more than 200 years. This spelling was also adopted

by Vahl, who wrote a comprehensive but insufficiently appre-

ciated commentary on Forskal’s work.

In a scholarly paper Friis & Thulin (1984) have argued that the

correct spelling is Forsskal, and this variant has appeared with

or without the diacritical sign in some recent literature including

an index of recommended author abbreviations (Meikle 1980).

Those who advocate such changes, it seems to me, are missing

the point. Forskal and his relatives at different times spelt their

name in different ways (Shakespeare was equally inconsistent),

which suggests that the precise spelling of their names was of little

importance to them. The citation ‘Elcaja roka Forskal’ is not

intended to be a statement about the correct spelling of its

author’s name but is merely a device to distinguish Forskal’s

plant from any others which may independently have been given

the same name.

Recent editions of the International code of botanical nomencla-

ture have encouraged instability of plant names in a misguided

quest for equity and scholarshp. It is true that the current edition

permits the proposal of nomina specifica conservanda, but this

may be too little and too late. Without a change of heart among

those who enjoy upsetting established nomenclature this opportu-

nity may be largely ineffective. The altering of conventional spel-

lings of author’s names has the same unfortunate consequences as

changing the names of plants. It can only serve to confuse the

non-specialist. It is recommended that for botanical purposes the

spelling of Forskal’s name as given in the Flora Aegyptiaco-Ar-

abica should be conserved, and that the formation of all Latin

scientific names based on it (past and future) should be standard-

ized. The Code as it stands, however, does not permit this and

needs to be altered. According to the Code, in Latin names, -a-

should be transcribed as -ao-. Other transcriptions (-aa- or -a-),

however, are preferable to some Scandinavians (see Friis & Thu-

lin 1984: 671). This illustrates the folly of trying to formulate the

universal standardization of such things, especially by retro-active

legislation.

158

Bothalia 16,2 (1986)

the reasons. Discussion, however, has persisted con-

cerning the validity of Forskal’s names (Heine

1968; Burdet & Perret 1983; Jeffrey 1985) and the

question of E. roka has been raised again by Friis

(1984), whose intention was to end this controversy

once and for all, and whose detailed and indepen-

dent enquiry led to conclusions which are virtually

identical to those of Dandy. Friis (1983) has also ex-

plained why Forskal’s names have been the source

of so much trouble.

Dandy’s reasons for rejecting E. roka are the most

convincing yet expressed and it would seem appro-

priate to publish them here in full — if only as an

example of the kind of expertise which is necessary

in order to establish the correct names of plants.

The following is taken from a letter dated 11 July

1963 sent by Dandy to Dr L.E. Codd, who was then

Director of the Botanical Research Institute, Pre-

toria, where the original is filed in the herbarium

under T. emetica.

‘Dear Dr Codd,

I am not surprised to have your letter concerning

Elcaja roka. This ‘name’ (like Cornus gharaf on the

same page of Forskal) has been misleading botan-

ists for some time. White consulted me about it for

Flora Zambesiaca, and it was after our joint investi-

gation that he reverted to the name Trichilia eme-

tica.

I have studied Forskal’s Flora Aegyptiaco-ar-

abica pretty closely in connexion with the Sudan

flora. Like so many works of its period, in the early

days of binomial nomenclature, it has its peculiari-

ties; and these are intensified by the fact that the

book was published posthumously from Forskal’s

manuscripts, so that it inevitably suffers from incon-

sistency and lack of finish.

The plan of the work is that the Flora itself (con-

sisting of systematic floristic lists for the regions con-

cerned) is contained in pages I-CXVI, and it is these

lists which give what may be described as Forskal's

intended (official) nomenclature. The lists include

localities, vernacular names, etc. but usually no des-

criptions. Descriptions of the new and more interest-

ing plants are given in the second part of the book

(‘Descriptiones’ pp. 1-220), and it is in this part that

the new genera, like Elcaja, are defined. The treat-

ment here, for the reason already stated, is uneven.

Sometimes the species under the new genera are

given a binomial, sometimes not; but in the latter

cases the missing binomial is usually supplied in the

floristic lists (pp. I-CXVI) and is of course validly

published by reference to the later part of the book.

In the case of Elcaja, however, it so happens that

the binomial is missing in both places, and this led

Chiovenda to take up Elcaja roka from p. XCV.

This ‘name’ appears with a lot of others in lists of

plants of medicinal and other importance which

Forskal prefaces to his actual floristic lists.

Now if these preliminary lists of species are closely

examined (instead of glanced at) it immediately be-

comes obvious that the ‘names’ used are not necessa-

rily binomials. Some of the names, especially of

common Linnaean species, are, it is true, binomials.

But others are just generic names or generic names

followed by vernacular names, and if these species

are looked up in the systematic parts of the book it

will be seen that Forskal has already provided a

binomial for most of them. From p. XCV, where El-

caja roka appears, we have the following examples:-

Cacalia edchera = C. odora pp. CXIX, 146

Amyris abu-scham — A. opobalsamum, pp. CX, 79

Cornus gharaf = C. sanguinea, pp. CC, 33

Thymus dousch = T. pulegioides? p. CXIV

Keura kadi = K. odorifera, pp. CXXII, 172

Tagetes benefsidj = T. dubia?, p. CXX

Cynanchum march = C. pyrotechnicum, pp. CVIII,

53

Ficus mudah = F. religiosa, pp. CXXIV, 180

From all this it is evident that in these preliminary

lists Forskal is referring to the species by any con-

venient designation, either by binomial or by ver-

nacular name, and that his ‘official’ names are those

given in the floristic lists. Perhaps if Forskal had

completed his manuscript he would have brought all

his references into line.

In my opinion, therefore, none of the ‘names’

listed by Forskal in his preliminary lists is to be re-

garded as a new binomial. If these ‘names’ were to

be accepted as binomials then all (not just Elcaja

roka) would have to be so treated and this would

lead to absurd results. The fact that Elcaja, evidently

by accident, failed to receive a binomial in the two

botanical parts of the book does not justify the tak-

ing up of Elcaja roka as the ‘missing’ binomial.

For the above reasons I consider that the name

Trichilia emetica Vahl should stand.

Kind regards,

Yours sincerely,

(Sgd) E. Dandy

Keeper of Botany,

British Museum (Nat. Hist.)’.

The differences between T. emetica and T. dregeana

For most of this century taxonomists dealing with

the flora of southern Africa failed to distinguish T.

dregeana from T. emetica , though some field work-

ers were well aware of their differences (e.g. the late

Prof. A. W. Bayer pers. comm.). Both species are,

or were formerly, of considerable economic impor-

tance and are frequently referred to collectively in

the literature under T. emetica or T. roka. It is often

impossible to know for certain which species is

meant. Acocks (1975) for instance only mentions T.

emetica , though the references on pp. 14, 19, 20 and

26 would appear to apply to T. dregeana.

In Flora Zambesiaca , White & Styles (1963:

298-302) set out the differences between these

species for the first time, and were able to distin-

guish them using a combination of characters —

shape of fruit and shape of leaflets, and for the latter

nervation, indumentum and colour when dry. It was

pointed out that most of these characters occasion-

ally break down but that if they are all used together

most specimens can easily be identified. De Wilde

(1968), however, believed that leaflet shape and in-

dumentum are of ‘no value at all’. These different

Bothalia 16,2 (1986)

159

conclusions possibly reflect a difference in approach.

In taxonomy, like should always be compared with

like. White & Styles specifically mention cases

where atypical material fails to show diagnostic

characters but they do not sufficiently stress the im-

portance of excluding such material from keys and

diagnoses, assuming that this was widely understood

and was normal practice. Further work has shown

that, if legitimate comparisons are made, there is no

difficulty in distinguishing these two species. The fol-

lowing comparisons deal with T. dregeana and T.

emetica only in southern Africa. It is in this part of

their range that their distributions interdigitate most

intimately and they come into closest contact. It is

here that the need for critical comparison is greatest.

In general, T. dregeana is a species of moist forest

and T. emetica occurs in riparian forest or various

types of ‘savanna’ in drier regions. In coastal Kenya,

however, T. emetica occurs in the canopy of quite

luxuriant moist forest. Here, in the shape of its leaf-

lets, but not in other respects it is atypical. This, of

course, does not necessarily weaken the specific dis-

tinctions in other parts of its range, nor indeed in

general, but such variation, unless carefully handled ,

may appear to do so.

(1) Structure of the fruit and inflorescence : the

most important difference between T. emetica and

T. dregeana is in the shape of the fruit. In the former

there is a distinct stipe (Figure 6); in the latter there

is none. At first sight this feature seems trivial, but it

is correlated with other features of the structure of

the inflorescence and infructescence and may be re-

lated to the precise way in which the arillate seeds

are displayed and presented to the animals which

disperse them. For a more general discussion of this

theme see Pannell & White (in press).

In T. dregeana the female inflorescence is few-

flowered and lax and occurs in the axils of well deve-

loped leaves. Normally only one fruit matures in

each inflorescence, occasionally up to three.

In T. emetica the flowers are borne in dense, con-

tracted panicles up to 50 mm long. Each inflores-

cence has c. 20 flowers. The pedicels are very short

and the flowers are almost touching. The inflores-

FIGURE 6. — 1, Trichilia dre-

geana, leaflet, x 0,4 (from

Thoms 5348 ); la, leaflet, x

0,4 and part of lower leaf-

surface, x 1,8 (both from

Strey 5340); lb, flower in

longitudinal section and

ovary in transverse section

(both x 2,8 and from Styles

333); lc, calyx and androe-

cium, x 2,8 (from Styles

333). 2, Trichilia emetica,

leaflet, x 0,4 (from

Liengme 577); 2a, leaflet,

x 0,4 and part of lower leaf

surface, x 1,8 (both from

Compton 31147); 2b, un-

opened capsule, x 0,4; 2c,

capsule just beginning to

dehisce, x 1,4; 2d, de-

hisced capsule viewed from

above, x 0,9; 2e, seed, x

1,4 (all from Bond s.n.).

160

Bothalia 16,2 (1986)

cences occur singly in the axils of leaves which are

separated by internodes less than 20 mm long or are

crowded in the axils of reduced foliage leaves which

are mostly caducous and form a terminal compound

inflorescence about 100 x 80 mm. Several fruits in

each inflorescence normally ripen (phot, on p. 120 of

Van Wyk 1972) and the stipe performs the function

of a pedicel. The less crowded fruits of T. dregeana

have no need for this. The ripe but undehisced fruit

of T. dregeana is 30-50 mm in diameter; that of T.

emetica usually less than 25 mm.

A comparative study of seed dispersal in these two

species would be useful.

(2) Leaflet shape and indumentum : no difficulty is

encountered in identifying specimens of T. emetica

and T. dregeana using leaflet characters alone,

though, because of variation, it is not possible to ex-

press the differences concisely in words. They can,

however, easily be conveyed by illustrations. Figure

6 illustrates two lateral leaflets from the distal half of

the leaf of T. dregeana ( Strey 5340 , Thorns 5348) and

two of T. emetica ( Compton 31147 , Liengme 577). It

is the shape of the apex that is significantly different

and can be described as follows:-

Apex of lateral leaflets shortly and acutely acuminate or

bluntly subacuminate (with the tip itself often shallowly

notched), nearly always showing a hollow curve

T. dregeana

Apex of lateral leaflets rounded, emarginate or broadly acute,

without a hollow curve T. emetica

In this comparison like is compared with like. If

terminal leaflets of T. emetica are compared with lat-

eral leaflets of dregeana the distinction is weakened

in that the leaf apex of the former sometimes shows

a hollow curve.

The differences given above seem to hold for all

southern African material with mature undamaged

leaves. All the specimens (149 gatherings) of these

two species that were available for study in the Na-

tional Herbarium Pretoria, were compared with the

four specimens mentioned above. A good match was

found in each case, except for 12 which were unsuit-

able for comparison in that they lacked wellpre-

served apices or represented the juvenile condition.

In T. dregeana the apex of the leaflet sometimes fails

to develop normally, possibly due to insect damage

or mechanical injury. Such specimens are rare and

should not be used in formal taxonomy. One of them

( Scheepers 1042) is illustrated by De Wilde (1968,

fig. 3Aa); another is White 14126b (FHO). It was

collected from a young 5 m tall tree growing in the

garden of Cornelius Grobbelaar in Pretoria, and was

the only leaf of its kind. All the other leaves (exemp-

lified by White 14126a) on this tree were normal and

were a good match for Strey 5340.

In southern Africa T. dregeana and T. emetica are

consistently different in the indumentum of their

leaves. Figure 6.

(3) Other differences : The leaves of T. dregeana

usually dry brown (not olive-green) and the leaflets

often have fewer lateral nerves. The flowers are

nearly always larger. All of these characters show

some overlap, though they are frequently useful in

identification.

Chromosome counts are few but a wide difference

has been reported (Styles & Vosa 1971: T. dregeana :

2n = ±360; T. emetica : 2n = 50).

The subspecies of T. emetica

De Wilde (1968: 50) recognizes two subspecies

which are almost completely allopatric, overlapping

only in Uganda. Subsp. emetica extends from Ethio-

pia and the Yemen to South Africa. Subsp. suberosa

De Wilde, which differs in its corky bark, more de-

ciduous habit and somewhat laxer inflorescence, oc-

curs from Senegal to Uganda.

Distribution and ecology of T. emetica and T. dre-

geana

Both species are chorological transgressors since

they occur in several of the regional phytochoria of

the Unesco/AETFAT/UNSO Vegetation Map of

Africa (White 1983a). Despite its wide distribution,

T. dregeana is fairly uniform in its ecology. White

(1978a) has referred to it as an ecological and choro-

logical transgressor, but it might be better to re-clas-

sify it as a sub-Afromontane near-endemic species

(see below). In its ecology T. emetica is much more

varied.

T. emetica extends from Senegal to Ethiopia and

southwards to about the latitude of Durban, pen-

etrating inland as far as the Caprivi Strip and north-

eastern Botswana. There is an outlying population in

the Yemen. In west Africa (subsp. suberosa), it is

apparently rare (at least in Nigeria) and its charac-

teristic habitat is Sudanian woodland (White 1983a:

105), especially on rocky hills. On the eastern side of

Africa it is one of the most characteristic trees of ri-

parian forest, especially where the rainfall is less

than 1 000 mm p.a. (White 1983a: 91, 117). In the

Zambezian Region it is also found in woodland and

wooded grassland on the more fertile soils (White

1983a: 95,96). In the east African coastal belt T.

emetica is locally an important constituent of semi-

evergreen forest as a pioneer species and where the

canopy is not too dense. On the Kenya coastal plain

it invades fire-protected, secondary wooded grass-

land with abundant Hyphaene compressa H. Wendl.

and, because of its rapid growth, it soon overtops the

palms. Also in Kenya, T. emetica occurs frequently

as a 20-25 m tall tree in the rather light canopy of

Combretum schumannii Engl, forest on coral lime-

stone. It regenerates freely inside the forest (White,

MS 1975).

In northern Natal, T. emetica is found in riparian

forest and locally, as in the Hluhluwe Game Re-

serve, in scrub forest on rocky slopes. From Mtun-

zini northwards it is found in various types of coastal

forest, both as a pioneer, and in the canopy where

the latter is no more than 12 m or so high.

T. dregeana is widespread in tropical Africa, but

shows major disjunctions between west and east

Africa, both north and south of the equator. It is al-

most confined to upland areas. In South Africa,

however, near Maputa and southwards from the Tu-

gela River mouth to its southern limit near the

Bothalia 16,2 (1986)

161

mouth of the Bashee River, it descends almost to sea

level. In west Africa it appears to be confined to a

few upland massifs from Guinea to Cameroun, oc-

curring between 800-1 600 m.

On the eastern side of Africa it has a scattered dis-

tribution from Ethiopia to South Africa. It chiefly

occurs in rain forest and related types on the moister

slopes of mountains, but usually at somewhat lower

altitudes than typical Afromontane vegetation. Thus

in Malawi it occurs between 650 and 1 600 m. It is a

characteristic member of mid-altitude rain forest in

which typical Afromontane species and lowland

species intermingle (White, Dowsett-Lemaire &

Chapman, The evergreen forest trees and shrubs of

Malawi’, in prep.). It has not been recorded in Mal-

awi from what White (1983a) calls Afromontane rain

forest (the submontane rain forest of Chapman &

White 1970), but it occurs very locally in lowland

rain forest towards its upper altitudinal limits as in

Mpita Forest, the lower slopes of Mt Mulanje and in

the Malawi Hills. To the north of Malawi most re-

cords are from medium altitudes though it ascends to

1 900 m in Ethiopia and 2 100 m in Uganda (De

Wilde 1968).

In Zambia, T. dregeana occurs very locally in ripa-

rian forest in the higher-rainfall areas. In Angola it is

found in the Dembos cloud forest (White & Werger

1978) between 800 and 1 000 m. T. dregeana also oc-

curs near Luki and Temvo in Bas Zaire between 200

and 500 m. In view of its consistently submontane

character elsewhere in tropical Africa, these low-al-

titude occurrences are puzzling. They are not with-

out parallel, however. Nuxia congesta , for example,

an Afromontane near-endemic species, locally has

small satellite populations at low altitudes, e.g. near

the mouth of the Zaire River (Leeuwenberg 1975;

White 1983b: Fig. 4a).

In southern Africa it occurs in forest in the moun-

tains of the NE Transvaal. Scheepers (1978) records

it from Cussonia spicata Thunb., Ficus sur Forsk.

kloof forest between 1 125 and 1 200 m in the Sub-

montane scrub forest belt and from climax Trichilia

dregeana , Cussonia spicata , Cryptocarya liebertiana

Engl, forest between 1 200 and 1 250 m in the Mon-

tane forest belt. In both these types Afromontane

and lowland forest species intermingle and they are

clearly related to the mid-altitude forests of Malawi

and elsewhere further north.

Further south in Natal and the Transkei, T. dre-

geana is predominantly a lowland species which

locally, as in Komgha District, ascends to ± 570 m.

It is a characteristic member of Tongaland-Pondo-

land lowland forest (White 1983a: 199) and has been

recorded from eight out of the 15 stands for which

quantitative information is available (Moll & White

1978: 580). In these forests, and in others for which

there are floristic records, e.g. Ngoye (Huntley 1965

as ‘ emetica ’) and Umtamvuma Nature Reserve

(White 1973, MS) Afromontane species, such as

Calodendrum capense (L.F.) Thunb., Drypetes ger-

rardii Hutch., Kiggelaria africana L., Podocarpus

falcatus (Thunb.) R. Br. ex Mirb., P. latifolius

(Thunb.) R. Br. ex Mirb., Rapanea melanophloeos

(L.) Mez and Xymalos monospora (Harv.) Baill. ,

occur, though lowland species are much more abun-

dant. North of Mtunzini, T. emetica appears to re-

place T. dregeana in coastal forest on the leeward-

side of dunes and in their hinterland. T. dregeana

however occurs in seasonal swamp forest at the

headwaters of the Sihadla River near Maputo (White

10475).

Habit

Both species develop wide umbrageous crowns

when growing in the open. In southern Africa, Tri-

chilia emetica rarely exceeds 12 m in height but can

exceed 20 m in east Africa.

The maximum height of T. dregeana south of the

Limpopo seems to be 20 m. In Malawi it can reach

twice that size. When growing in the forest it devel-

ops a long straight bole and relatively narrow crown

no wider than the height of the tree (photo in Palmer

& Pitman 1972). In 1940 the famous Thunder Tree

in Mitchell Park, Durban, though less than 20 m

high, had developed a crown nearly twice that di-

ameter. The bole which was 5,5 m across was

branched at about 2 m and supported massive wide-

spreading limbs. The tree was said to have made no

appreciable increase in size during the previous 50

years (A. P. D. McClean in litt. 19 Jan. 1940, in

PRE; Cuthbertson 1950, as ‘ emetica ’).

Fruit structure and dispersal

In T. dregeana and T. emetica, as the capsule

opens the placenta breaks up and its dismembered

parts remain attached to the separating valves. If

both ovules in a locule develop, each seed resembles

a somewhat distorted segment of an orange; they

have two flat sides and one outer curved surface.

That side which is in contact with the ‘sister’ seed is

larger and flatter than the opposite one w-hich is ap-

pressed to the septum. The outer surface is hence

asymmetric. The red aril covers the whole seed ex-

cept for a patch on the outer face where the black

testa is exposed. When the capsule begins to open,

this black ‘eye’ is hidden, but as the valves continue

to separate it frequently becomes visible.

Frost (1980) records eight species of bird as eating

the arils of T. emetica at Mtunzini in Natal. There

are no comparable records for T. dregeana from

South Africa. In Malawi it is eaten by Onychogna-

thus walleri starlings (F. Dowsett-Lemaire, unpub-

lished).

7. PSEUDOBERSAMA Verde.

Pseudobersama mossambicensis (Sim) Verde, in

Journal of the Linnean Society, Botany 55: 504, fig.

1; White & Styles: 305, fig. 60 (1963). Type: Mozam-

bique, without locality, Sim 5204 (not located); fig.

23 in Sim (1909), lectotype here designated.

Bersama mossambicensis Sim: 34, fig. 23 (1909).

Typification

Neither Verdcourt nor White & Styles succeeded

in locating the type, and it has not subsequently

come to light. Sim re-numbered many of his speci-

mens and his collection was divided between several

herbaria. The only Sim specimen that I have seen

162

Bothalia 16,2 (1986)

(PRE 21178) is possibly part of the orginal material

though it is not a very good match for Sim’s rather

sketchy illustration. As Verdcourt has said the latter

is unmistakable. In these circumstances it seems that

Sim’s figure should be designated as a lectotype

(Art. 7.4).

Distribution and ecology

P. mossambicensis has a scattered distribution in

coastal forest from Kenya to Natal, and is therefore

a Zanzibar Inhambane/Tongaland-Pondoland link-

ing species, or east African coastal endemic. In

southern Africa it is only known from a few forests

in northern Tongaland where it is locally a common

canopy tree (Tinley 321).

Fruit structure and dispersal

P. mossambicensis is unique in the family in hav-

ing a woody capsule which is massive in its construc-

tion in relation to the small arillate seeds contained

in it. It seems that the plant is using much more of its

resources for protecting the developing seed than for

attracting and ‘rewarding’ its dispersers (Pannell &

White 1985). Nothing, however, is known of the re-

productive biology of this species. When more is

known, P. mossambicensis might provide clues to

the evolution of wind-dispersed Meliaceae such as

Entandrophragma.

8. ENTANDROPHRAGMA C. DC.

A genus of 11 species. Six species, namely, E. an-

golense (Welw.) C. DC., E. candollei Harms, E.

congoense (De Wild.) A. Chev., E. cylindricum

(Sprague) Sprague, E. palustre Staner and E. utile

(Dawe & Sprague) Sprague, occur in the Guineo-

Congolian rain forest region. E. excelsum (Dawe &

Sprague) Sprague is an Afromontane rain forest

species. There are three Zambesian endemics or

near-endemics: E. caudatum (Sprague) Sprague, E.

delevoyi De Wild, and E. spicatum (C. DC.) Spra-

gue. The remaining species, E. bussei Harms, which

is related to, but distinct from, E. spicatum occurs

only at and immediately adjacent to the southern ex-

tremity of the Somalia-Masai region.

The rain forest species emerge above the canopy

and are among the tallest of African trees. The other

species, though shorter, also emerge from the drier

types of forest, woodland and thicket in which they

occur. All species produce mahogany. That of E.

utile, known in the timber trade as ‘Utile’ is highly

esteemed. The southern African species are too rare

to be of commercial importance, and in common

with the other species have not been successfully

grown in plantations.

Entandrophragma is unique among southern Afri-

can Meliaceae in having wind-dispersed, winged

seeds. Nothing is known about the mechanism of

dispersal. In Nigeria the seeds of E. angolense are

shed towards the end of the dry season but several

weeks before the rains break. The five valves are

shed leaving the seeds packed along each face of the

central column. They stay like this for a week or

more until a sudden gust of wind liberates them

when they rotate as they fall to the ground. Few are

carried far beyond the parent tree and most are de-

stroyed by predators, especially mice. Some, how-

ever, travel considerable distances and saplings have

been found up to 0,8 km from the nearest tree from

which the seeds could have come (J. D. Chapman in

Pannell & White 1985).

In the southern African species dispersal is pre-

sumably broadly similar but the details of seed liber-

ation are different. The capsule dehisces from the

apex (see Figure 19 in White & Styles (In press, a)

and other illustrations cited therein) and the valves

move outwards but remain firmly attached to the

base of the capsule which now looks like a shuttle-

cock. The seeds, however, remain firmly attached to

the columella, and presumably they also are liber-

ated by the action of strong wind.

1. Entandrophragma caudatum (Sprague)

Sprague in Kew Bulletin 1910: 180 (1910).

This species is confined to the southern part of the

Zambezian Region, except for a slight intrusion into

the northern part of the Tongaland-Pondoland Re-

gion. It is not very variable. One specimen (De Win-

ter 7737 from near Louis Trichardt) is unusual in

having leaflets broadly cordate or hastate at the

base. The leaves, however, are not attached and

may have come from a young plant.

2. Entandrophragma spicatum (C. DC.) Spra-

gue in Hooker’s leones Plantarum 31: in nota sub

fig. 3023 (1915).

This species is confined to a small area at the east-

ern extremity of the Zambezian Region and extends

into the Zambezia/Kaokoveld-Mossamedes tran-

sition (White 1983: 191) which connects the Zambe-

zian and Karoo-Namib Regions. Other Zambezian

species, e.g. Colophospermum mopane (Kirk ex

Benth.) J. Leonard (Figure 12 in Volk 1966) extend

to the fringes of the Mossamedes-Namib desert in

this region of abrupt climatic gradients.

DISCUSSION

Chemistry and the taxonomy of the Meliaceae

(a) Introduction

According to Harborne & Turner (1984), taxo-

nomy, thirty five years ago, entered a new Biochem-

ical phase (p. 36). The purpose of their book is to

review up to the end of 1982 the state and potential

of this approach to plant systematics (p. viii). To

judge from their ‘philosophical and pragmatic ra-

tionale’ (as summarized on p. 45 and from state-

ments made elsewhere) they equate taxonomy with

phylogeny, and make insufficient distinction be-

tween descriptive and historical biology. Although

they refer (p. 33) to the importance of gross morpho-

logy at the present time, they imply that chemistry

will ultimately prove to be more important. In con-

cluding a chapter on the application of chemistry at

the family level in a section which deals with second-

ary metabolites they say that ‘it appears obvious that

chemical approaches both micromolecular and

macromolecular will soon yield a classificatory bul-

wark which is likely to withstand the whim and

whine of any number of newly inspired intuitional

Bothalia 16,2 (1986)

163

workers using the long-overworked, now classical,

megamorphic approaches’ (p. 312), whatever that

may mean. Elsewhere (p. 291), they say that ‘second-

ary compounds are primarily useful in taxonomic

studies at the species and generic level’.

I believe that Harborne & Turner underestimate

both the achievements and potential of the tradi-

tional approach, and that their particular advocacy

is, at best, premature and may never be substan-

tiated. Recent work on the Meliaceae suggests that,

in that family at least, secondary compounds are

more useful at higher taxonomic levels than at genus

and species level.

(b) Limonoids and the Meliaceae

Although much work remains to be done, the sec-

ondary compounds of the Meliaceae have probably

been as thoroughly studied during the last 25 years

as any predominantly tropical family of comparable

size and diversity. Work on the taxonomy and chem-

istry was done independently though the principal

investigators have maintained close contact. Some

tentative historical interpretations are emerging

from the taxonomy (Pannell & White, in press) but

the primary aims so far have been to delimit and de-

scribe taxa as objectively as possible, and to study

their ecology.

Chemically, the Meliaceae is characterized by the

presence of limonoids, a group of oxidized triter-

penes. According to Taylor (1984) more than 250

limonoids have been extracted and identified from

54 species belonging to 23 genera. Limonoids have

been found to occur in nearly every member of the

family so far investigated. Elsewhere, they are only

known from Harrisonia abyssinica, currently placed

in Simaroubaceae, a few Rutaceae, and Cneoraceae,

three families usually placed in the same order as

Meliaceae. Of these families the Meliaceae is the

most diverse in its limonoid profile. In their limo-

noid chemistry the members of the Meliaceae collec-

tively form an extremely tightly knit and sharply de-

fined group.

(c) The position of Ptaeroxylon and Nymania

The inclusion of both genera in the Meliaceae has

been questioned. Both were examined for limo-

noids. Ptaeroxylon (see p. 144) was found to lack

them, so confirming its exclusion from Meliaceae,

on other grounds, by Leroy (1959, 1960) and White

& Styles (1966). By contrast, Nymania does have

limonoids (p. 145) and White (present study), after

an independent assessment of previous work, ac-

cepts these chemical findings as an additional reason

for including it in Meliaceae. Nymania is a genus of

special interest. In its leaves, flowers and fruits it

looks most un-meliaceous and it is easy to under-

stand why some South African botanists want to ex-

clude it. On visual inspection it seems to have little

in common with other South African members of the

family, but its distinctive features can largely be ex-

plained by its ecology. Ecologically, it is one of the

most specialized genera in the family. It is a bird-pol-

linated, semi-desert xerophyte with wind-dispersed

capsules. When it is studied in relation to the ecolog-

ical, chorological and morphological patterns of the

family as a whole its membership is seen to be more

convincing. Its chemistry seems to clinch the matter

of its inclusion, but provides no clues about its clos-

est relatives. Its limonoids belong to a group which is

widely distributed in the family. The decision to

place it in a unigeneric tribe next to Turraeeae was

taken on grounds other than chemistry.

(d) Southern African Trichilia: chemistry and the

taxonomist’s eye

In herbarium taxonomy, when preserved material

is sparse and field experience limited, mistakes are

often made, but they are easily rectified as know-

ledge increases. This was so for Trichilia emetica and

T. dregeana (p. 158). Now that they have been

shown to differ, everyone recognizes them, both in

the field and in the herbarium. Their distinctive fea-

tures are discussed and illustrated in the present ac-

count, in which it is shown that, provided compari-

sons are carefully made, identification is easy. When

the specific differences are known it is possible to

classify herbarium specimens as quickly as they can

be handled, that is, in effect, instantaneously. Iden-

tification in the field is not more difficult (J. D.

Chapman; I. Friis pers. comm.; F. White pers.

obs.). On the other hand there is no evidence to sug-

gest that these two species are not very closely re-

lated. Phytochemical evidence superficially appears

to be at variance, though to a chemist with a knowl-

edge of the structures of the compounds concerned,

there may be a simple explanation (D. A. H. Taylor

in litt., 26 February 1986).

Taylor (1984) has classified the limonoids of Me-

liaceae into 10 groups based on an increasing degree

of oxidation. T. emetica is placed in group 2, the Ha-

vanensis Group alongside Azadirachta, Khaya, Me-

lia, Toona and Turraea, to mention only those gen-

era which are indigenous or cultivated in southern

Africa. T. dregeana has limonoids in groups 9 and

10; both groups include Toona and Nymania.

(e) Conclusions

Limonoid chemistry is compatible with the way

the family has been circumscribed using traditional

means. But within the family the distribution of the

different classes of limonoids is not always closely

correlated with morphology. The reasons for this are

under investigation (Taylor, Pannell, Styles &

White, in prep.), though there are no indications

that, for Meliaceae at least, the traditional approach

to taxonomy is in danger of being superseded. There

are, however, some indications that a deeper knowl-

edge of limonoid chemistry would increase ecologi-

cal understanding. This subject, however, remains

largely unexplored.

Taxonomy as a visual art

It was said above that in some circumstances plant

species can be identified ‘by eye' with great rapidity.

If this were not so, the great masters of the past, on

whose labours present-day and future taxonomy is

founded, could not have been so productive. Picto-

rial representation in taxonomy, however, with

some notable exceptions, is insufficiently used. In

White & Styles (In press, a) every species has been

illustrated in sufficient detail to make identification

possible. The text merely draws attention to and

164

Bothalia 16,2 (1986)

elaborates on the main differences between taxa,

and provides additional historical and biological in-

formation.

For two species, Ekebergia capensis and Turraea

obtusifolia, complex patterns of geographical varia-

tion are depicted by means of pictorialized distribu-

tion maps (Figures 3 & 5). Although this method has

been in use for more than 30 years, it is rarely re-

sorted to and many published accounts of taxonomi-

cally difficult complexes are impossible to under-

stand because of its lack. In my experience the picto-

rialized distribution map can often display the evi-

dence on which taxonomic judgement should be

based, more effectively than any other means.

The Meliaceae and the chorology of southern Africa

The Meliaceae has many more species and is much

more diverse in lowland tropical rain forest than in

any other type of vegetation. Presumably, it under-

went most of its differentiation there. In common

with some other predominantly tropical rain forest

families, e.g. Fabaceae: Caesalpinioideae, it is also

well represented in drier types.

Most of southern Africa lies outside the tropics

and there is little rain forest. Both in Australia,

which is situated at similar latitudes, and in South

Africa very restricted taxa occur as well as species

which are very widely distributed in the tropics to

the north. The distributions in southern Africa of all

species indigenous there, are indicated on Figure 7

and on Figure 8 which also record distribution in re-

lation to the phytochoria of White (1983a). There

are five types of distribution:

(a) two species, Entandrophragma spicatum and

Turraea zambesica, are confined to the tropics, but

only occur towards its southern limits;

(b) five species, Nymania capensis, Turraea pul-

chella, T. streyi, T. obtusifolia and Ekebergia ptero-

phylla, lie wholly or predominantly outside the tro-

pics . The first three are taxonomically very isolated ;

(c) Entandrophragma caudatum occurs mostly in-

side the tropics but only in the southern part of the

Zambezian Region;

(d) Pseudobersama mossambicensis is confined to

the forests of the east African coastal belt;

(e) the remaining species, Ekebergia capensis, Tri-

chilia dregeana, T. emetica, Turraea floribunda and

T. nilotica are widespread in Africa and occur in sev-

eral phytochoria.

A diverse pattern like the one summarized above

confirms the need for a flexible, non-hierarchical

chorological framework such as that used for the

FIGURE 7. — Density map of Meliaceae in southern Africa showing the total number of species in each degree square.

Bothalia 16,2 (1986)

165

FIGURE 8. — Map of Meliaceae in southern Africa showing the occurrences of the 14 indigenous species in each degree square and

the approximate boundaries of the regional phytochoria of White (1983a). II, Zambezian regional centre of endemism; V,

Cape regional centre of endemism (enclaves of Karoo and Afromontane vegetation not shown); VI, Karoo-Namib regional

centre of endemism; VIII, Afromontane archipelago-like regional centre of endemism; XIV, Kalahari-Highveld regional

transition zone; XV, Tongaland-Pondoland regional mosaic. 1, Nymania capensis-, 2, Turraea nilotica-, 3, T. zambesica- 4, T.

obtusifolia ; 5, T. floribunda\ 6, T. pulchella\ 7, 7. streyi; 8, Ekebergia capensis; 9, E. pterophylla; 10, Trichilia dregeana; 11,

T. emetica ; 12, Pseudobersama mossambicensis ; 13, Entandrophragma caudatum ; 14, E. spicatum.

AETFAT Vegetation Map of Africa. For some pur-

poses at least, this approach seems preferable to

‘simple areal definitions’ such as that adopted by

Goldblatt (1978: 375) for the Cape Floristic Region,

notwithstanding some obvious administrative advan-

tages of the latter. A special feature of the AETFAT

system is that the distinctness of the great regional

centres of endemism is enhanced by the recognition

of regional transition zones, and regional mosaics of

complex chorological affinity. For the Cape Region

the exclusion of large enclaves of non-fynbos vegeta-

tion serves a similar purpose. Southern African Me-

liaceae illustrate this theme. Thus:

(a) the Kalahari-Highveld Transition Zone has no

endemic Meliaceae but two species cross its limits as

marginal intruders;

(b) the chorological heterogeneity of the Tonga-

land-Pondoland Mosaic is confirmed by the occur-

rence of: (i) two endemic species of Turraea (T. pul-

chella and T. streyi) of limited geographical extent

which comprise a very distinct section; (ii) two Ton-

galand-Pondoland near-endemic species (Ekebergia

pterophylla, Turraea obtusifolia) which extend a

short way into the Zambezian Region; (iii) one mar-

ginal intruder (Pseudobersama mossambicensis)

from the Zanzibar-Inhambane Region; (iv) one mar-

ginal intruder (Entandrophragma caudatum) from

the Zambezian Region; (v) one marginal intruder

(Nymania capensis) from the Karoo-Namib Region;

and (vi) four chorological transgressors (Ekebergia

capensis, Trichilia dregeana, T. emetica, Turraea het-

erophylla);

(c) the distribution of Nymania capensis supports

the practice of restricting the Cape Region to areas

dominated by fynbos and related types of vegetation

and excluding from it extensive enclaves of forest,

bushland and Karoo (see Figures 1 & 2).

The function of taxonomic characters

Taxonomy is improved when function is under-

stood; and historical interpretation (when it is pos-

sible at all) can be approached with greater confi-

dence when we know how organisms ‘work’ and in-

teract. In the conventional, museum-based approach

to taxonomy, differences between related taxa are

frequently expressed in stereotyped terms (e.g. ‘fruit

166

Bothalia 16,2 (1986)

dehiscent or indehiscent’) which may conceal a mul-

titude of differences. The latter are liable to escape

detection until the importance of ecology in taxo-

nomy is realized. This has been convincingly shown

by the work of Hopkins (1983, 1984) on the pan-

tropical bat-pollinated genus Parkia (Fabaceae:

Mimosoideae) and of Panned & Koziol (in press) on

the Far Eastern bird- and primate-dispersed genus

Aglaia (Meliaceae). In several places in the fore-

going account both the potential significance and our

ignorance of the ecology of southern African Melia-

ceae has been pointed out, particularly in relation to

pollination and dispersal. I hope that South African

botanists will regard this as a challenge to discover

more about their living flora. They may need the col-

laboration of zoologists but the subject is too import-

ant to be left to zoologists alone.

ACKNOWLEDGEMENTS

I am grateful to the Director of the Botanical Re-

search Institute and his staff for their assistance dur-

ing a visit to Pretoria early in 1985. I. Friis, D. J.

Mabberley, C. M. Panned, T. D. Pennington, B. T.

Styles and D. A. H. Taylor commented on the

manuscript and helped in other ways. Valuable in-

formation was also provided by W. R. Bainbridge,

R. K. Brummitt, A. A. Gubb, T. K. Lowry and R.

C. Palmer. Special thanks are due to Rosemary Wise

and her son Richard for preparing the illustrations,

and to Cynthia Styles, who typed this paper and the

flora accounts.

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Bothalia 16,2: 169-180 (1986)

Studies in the genus Riccia (Marchantiales) from southern Africa. 4.

Three endemic species, R. natalensis , R. microciliata sp. nov. and R.

mammifera sp. nov.

O. H. VOLK* and S. M. PEROLD**

Keywords. Ciliatae , Marchantiales, Riccia species, southern Africa, taxonomy

ABSTRACT

Three endemic species of the group Ciliatae' (subgenus Riccia sectio Riccia) are dealt with. The description of

R. natalensis Sim is emended, as Sim’s original description (1926) was sketchy and Arnell (1963) had no fresh

material to examine, which resulted in some inaccurate observations; R. microciliata Volk & Perold is a diminutive

new species with conspicuous, arched marginal and occasionally dorsal cilia, whereas R. mammifera Volk & Per-

old, another new species, has enlarged cells (or short cilia) along the thallus margins.

UITTREKSEL

Drie endemiese spesies van die groep 'Ciliatae' (subgenus Riccia sectio Riccia ) word behandel. R. natalensis Sim

word breedvoerig beskryf, aangesien Sim (1926) se oorspronklike beskrywing daarvan baie kort was, en Arnell

(1963) geen vars materiaal gehad het om te ondersoek nie, wat gelei het tot onakkurate waameming; verder word

twee nuwe spesies wat ook tot die ‘Ciliatae’- groep behoort, beskryf: R. microciliata Volk & Perold met gekromde

silia en R. mammifera Volk & Perold met vergrote selle langs die tallus-rande.

1. Riccia natalensis Sim in Transactions of the

Royal Society of South Africa 15; 9 (1926); Arnell:

18 (1963).

TYPE. — Natal, 2730 (Vryheid): Scheepers’s

Nek (-DC), March 1915, Sim 8228 (PRE, holo.!;

BOL!).

R. natalensis is described in detail, as Sim’s origi-

nal description was very brief and Arnell had no

fresh material to examine, which led to some inaccu-

rate observations.

Thallus monoicous, perennial, bright green, in

more or less complete rosettes (Figure 1A), in greg-

arious patches or scattered, medium-sized to large,

furcate, sometimes bifurcate, branches moderately

divergent, often only one branch well developed, lig-

ulate or obovate, wider towards apex, up to 12 x 4

mm, 4—8 times broader than thick, terminal seg-

ments 3-5 mm long; apex shortly emarginate, upper

surface deeply furrowed apically, more proximally

slightly concave to almost flat as groove widens and

becomes shallow (Figure IB); margins raised,

tumid, subacute to rounded, slightly attenuate,

forming a short wing with numerous cilia (Figure

ID), flanks sloping up and outwards, pale brown to

violet with age; ventral surface slightly rounded,

green, when dry, pale green dorsally, only apex and

distal sides partly inflexed, with cilia erect and con-

spicuous. Cilia crowded at apex and younger distal

margins, becoming sparser and more distant proxi-

mally, never present over sporangia, triangular,

160-300 (-400) pm long, 30-50 pm wide or base, of-

ten bulging on one side, gradually narrowing to

blunt or subacute tip, straight or slightly curved (Fig-

* Botanische Anstalten d. Univ. Wurzburg D 8700. Germany,

BRD.

** Botanical Research Institute, Department of Agriculture and

Water Supply, Private Bag X101, Pretoria 0001. RSA.

ure IE), hyaline, surface finely granulate (Figures

ID, 2D), when dry, somewhat flattened, slightly

twisted, with one or both margins inflexed, giving

walls and apex a partly thickened appearance (Fig-

ure IE), similar to cilia of R. trichocarpa (see Volk

1983: Table II). Anatomy of thallus: cells of dorsal

epithelium in one layer, hyaline, broadly globular or

mammillate (Figures 1C, 2C), but sometimes upper

wall collapsed and cells cup-like; air-pores triangular

or 4-sided; in section (Figure 1G), assimilation tissue

(chlorenchyma) almost \ the thickness of thallus,

cells isodiametric or shortly rectangular, in vertical

or sloping columns of 6-8 (-10) cells, enclosing 4-6-

sided air-canals 20-40 pm wide; storage tissue nearly

\ the thickness of thallus, cells rounded, irregularly

arranged, up to 50 pm wide; rhizoids both smooth

and tuberculate, about 20 pm wide. Scales small,

about 300 x 160 pm (Figures IF, 2B) hyaline, not

persistent, cells isodiametric, thin-walled. Antheri-

dia numerous in distal part of groove, hyaline os-

tioles projecting about 100 pm. Archegonia scattered

along median part of lobes, necks purple. Sporangia

2-8 per lobe, bulging dorsally, overlying epithelium

sometimes blotched with purple, with 100-200

spores. Spores (95-) 110-115 pm in diameter, tri-

angular-globular, polar, straw-coloured, pellucid;

with broad undulating wing up to 10 pm wide, mar-

gin smooth or finely crenulate, at marginal angles

incised or with a pore (Figure 3F); distal face convex

to slightly flattened, reticulate with 6-9 rounded or

angular areolae across diameter (Figures 1H, 2F,

3C, D), areolae about 15 pm wide, bordered by low,

smooth ridges, raised into blunt tubercles at nodes;

proximal face with apex usually blunt (Figures II,

2E, 3A, B & E) triradiate mark not sharply delin-

eated, each facet with 10-13 rounded areolae, 10-15

pm wide, or incompletely reticulate to vermiculate

(Figure II). Chromosome number n = 9 (Bornefeld

1984) (Figure 1J).

170

Bothalia 16,2 (1986)

FIGURE 1. — Riccia natalensis (5. M. Perold 307, PRE). Structure of thallus, spores and chromosomes. A, part of rosette; B,

transverse section of lobe; C, mammillate epithelial cells; D, cilia at margin; E, cilia with inflexed margins; F, scale; G,

archegonium and 2 antheridia; H, distal spore face; I, proximal spore face; J, chromosomes. (A-I by O. H. Volk; J by T.

Bornefeld. Drawings by G. Condy.) Scale bars on A, B = 2 mm; C-G = 100 pm; H-I = 50 pm; J = 1 pm.

Bothalia 16,2 (1986)

171

FIGURE 2. — Riccia natalensis ( S . M. Perold 430, PRE). Thallus, cilia and spores. A, surface view of thallus; B,

dorsal cells and margin with cilia and small scales; C, globose dorsal cells; D, tip of cilium, surface granu-

lose; E, proximal spore face; F, distal spore face. (A-D, SEM micrographs; E, F, LM (light microscope)

by S. M. Perold.) Scale bars on A-D = 50 pm; diameter of spores on E, F ± 100 pm.

R. natalensis is easily recognized by the conspicu-

ous marginal cilia, the broad, thin thallus and by the

bright green dorsal colour. It is a relatively scarce

species and infrequently collected; it is endemic to

the south-eastern Transvaal, eastern Orange Free

State and northern and central Natal (Figure 4), and

has not been found in the drier, western parts of

southern Africa. It appears to be hydrophytic as it

grows on damp, loam-rich soil, sometimes on black

turf, near seepages, and on streambanks and is often

associated with R. stricta (Trev.) Duthie and species

of Anthoceros, Selaginella, Eragrostis and Crassula.

Soil pH 5,1 and 6,0.

R. natalensis is placed in the ‘Ciliatae’ -group (sec-

tion Riccia), together with the other ciliated species

found in southern Africa; R. crozalsii Lev., R. tri-

chocarpa Howe (= R. canescens Steph.) and the two

new spp. R. microciliata and R. mammifera.

Sim (1926) described the epithelium of the thallus

as ‘about 2 layers of larger, much laxer cells’, but

there is only one layer of cells present. He also states

that ‘all along the outer portion of the thallus surface

rise pellucid, single-celled mamillae numerous and

irregular, giving an appearance of white scales to the

thallus when it is dry.’ The ‘mamillae’ clearly refer to

172

Bothalia 16,2 (1986)

FIGURE 3. — Riccia natalensis ( S . M. Perold 307 , PRE). Spores. A, proximal face; B, viewed from side; C, D,

distal face; E, apex; F, marginal pore. (SEM micrographs by S. M. Perold). Scale bars = 50 pm.

the cilia along the margins. Arnell (1963) remarks

that the epidermal cells were destroyed in the type

specimen when he examined it and he could not con-

firm Sim’s observation that these cells are mammil-

late in the lateral portion of the thallus. In his key to

the Riccia species, Arnell places R. natalensis in the

group without cilia (!) at the thallus margin, and in-

cludes it with those species where the dorsal epithe-

lium consists of free cell pillars, R. albomarginata

Bisch. and R. concava Bisch. (section Pilifer Volk

1983). He seems, therefore, to have misinterpreted

Sim’s reference to ‘mamillae’ and took it to apply to

the epithelial cells. Furthermore he describes the ci-

lia as smooth, whereas they are granulate. Both Ar-

nell and Sim fail to note the presence of the small,

hyaline scales and Sim reports the number of spores

in a sporangium to be 20-30.

SPECIMENS EXAMINED

TRANSVAAL. — 2428 (Nylstroom): Loubad, NW of Nyl-

stroom (-CA), S. M. Perold 816 (PRE). 2529 (Witbank): Loskop

Dam Nat. Res., Rhenosterhoek (-AD), Reid 1107 (PRE); Farm

Bankfontein, 20 km N of Middelburg, Cycad Trail (-CB), S. M.

Perold 103 (PRE); near turnoff to Balmoral, next to N4 road to

Witbank (-CC), S. M. Perold 430 (PRE). 2530 (Lydenburg): near

Marmerkop Sta. at turnoff to Boschhoek (-AB), 5. M. Perold 421

(PRE). 2629 (Bethal): 17 km W of Hendrina (-BA), 5. M. Perold

352 (PRE); 5 km N of Hendrina (-BA), 5. M. Perold 355 (PRE).

2630 (Carolina): 45 km to Lake Chrissie on road from Lochiel

Bothalia 16,2 (1986)

173

(-AB), S. M. Perold 1048 (PRE); Knock Dhu Farm, 13 km SE of

Lake Chrissie (-AD), Germishuizen 2888 (PRE); opposite Lake

Chrissie (-AD), 5. M. Perold 1057 ( PRE). 2730 (Vryheid): Farm

Oshoek, Distr. Wakkerstroom (-AD), S. M. Perold 679 (PRE).

NATAL. — 2930 (Pietermaritzburg): between Mooirivier and

Rosetta (-AA), S. M. Perold 307 (PRE); Van der Bijl CH 1134

(PRE); Volk 841633 (M, PRE).

O.F.S. — 2728 (Frankfort): Petrus Steyn, at turnoff from road

R26 (-CA), J. M. Perold 30 (PRE). 2927 (Maseru): 12 km S of

Ladybrand on main road R26 (-AB), J. M. Perold 38 (PRE).

2. Riccia microciliata Volk & Perold , sp. nov.

Dioica, perennis. Frondes parvae, (l-)3-4(-5)

mm longae, minusquam 1 mm latae, plusminusve

1 mm crassae, repetite irregulariter furcatae, lin-

eares, singulares vel in rosulis ad 10 mm latis, glau-

cae, apicibus obtusis, minute emarginatis, non nisi

proximaliter sulcatae, marginibus ± obtusis et tumi-

dis, antice ciliis gracilibus, rigidulis, 150 ad 300 pm

longis, prope basin bulbosis, 30-40 pm latis, saepe

arcuatis recavisque, canaliculatis, parietibus inaeqa-

liter crassis munitis; in sicco marginibus inflexis,

brunneolis; stratum assimilans dimidium transsectio-

nis occupans, ± cellulae virides in columnis perpen-

dicularibus, canalibus tri- vel quadrangulatis includ-

ens; cellulae epithelii unistratosae globosae ad cilii-

formes, inaequilongae, cum stomatibus tri- ad qua-

droangulatis. Squamae parvae, inconspicuae,

subnigrae vel hyalinae. Sporangia supra ± ciliifera.

Sporae triangulate-globosae, polares, atrofuscae,

80-90 pm diametro, non alatae, distaliter irregular-

iter reticulatae vel vermiculatae, areolae rotundae

sive ovatae, parietibus crassis, 10-12 areolis in di-

ametro, proximaliter linea triradiata indistincta, or-

namentatione facettorum distaliter aequans. In statu

adverso bulbillos formans. Chromosomatum nume-

rus n = 8 (Bornefeld 1984).

TYPE. — Transvaal, 2530 (Lydenburg): Sabie,

immediately W of town, near bridge over Sabie

River; on shallow soil over flat, weathered, granitic

rock outcrops (-BB), 1984.04.15, S. M. Perold 383

(PRE), with R. okahandjana S. Arnell and black Cy-

anophyceae. Soil pH 6,1.

Thallus dioicous, perennial, glaucous green, in

complete or incomplete rosettes up to 10 mm across,

small; branches simple or asymmetrically furcate,

branches irregularly arranged, narrowly divergent

(Figure 5A), (1-) 3-4 mm long, less than 1 mm

broad, about as broad as thick, linear-ovate, apex

obtuse, shortly emarginate; upper surface with nar-

row, deep groove, soon broad and almost flat (Fig-

ures 5B, 6A), margins rounded, with numerous cilia;

flanks steeply ascending, dark violet; ventral surface

rounded, green, or with brown bands across (Figure

5C); when dry (Figure 5B), margins inflexed, arched

cilia interlocking, flanks turning brown with age. Ci-

lia in several rows (Figures 5F, 6D), crowded at apex

and along margins, sparse proximally, occasionally a

few on upper surface of thallus; finely striated, hya-

line, usually bent over surface, markedly channelled

(Figures 5F, 6E), with one of the sides more deeply

inflexed, giving it a much thickened appearance,

(80-) 175-300 pm long, base bulbous (Figure 6B, C),

35 pm wide, narrowing to blunt tip. Anatomy of thal-

lus-. dorsal epithelial cells in one layer, 20-30 pm

wide, 30-40 pm high, frequently some up to 100 pm

high and 50 pm wide (Figure 5E), thin-walled; air-

pores 3^1-sided; in section (Figure 5D), assimilation

tissue (chlorenchyma) M the thickness of thallus,

cells isodiametric, 25 x 25 pm, in vertical columns of

about eight cells, enclosing narrow 3^1 (-5)-sided

air-canals; storage tissue with round or angular cells,

30 pm wide, irregularly arranged; rhizoids arising

from flattened epidermal cells, mostly smooth, occa-

sionally tuberculate, up to 25 pm wide. Scales small,

not quite reaching to thallus margin, purple or partly

hyaline, cells oblong, 4-6-sided, 60 x 25 pm. Anthe-

ridia with prominent hyaline ostioles, about 125 pm

long, in middle part of male thalli. Archegonia with

purple necks and hyaline tips, scattered along

groove, usually crowned by several cilia. Sporangia

containing 100—170 spores each, 1-3 per lobe, caus-

ing bulging of overlying purple-coloured tissue, with

only 1 or 2 cilia, and sometimes none remaining.

Spores 80-90 pm in diameter, triangular-globular,

polar, chestnut-brown to almost black, becoming

opaque with age, wingless, margin crenate; pore

usually present at marginal angles, 5 pm across (Fig-

ure 7D); ornamentation similar on all faces, reticu-

late to vermiculate (Figure 7B); distal face with

10-12 round or oval areolae across diameter (Figure

7E, F), about 7,5 pm wide, some adjacent areolae

confluent, ridges surrounding areolae broad and

thick, rounded, slightly raised at nodes, sometimes

anastomosing and forming short, undulating, ver-

micular ridges; proximal face with apex blunt (Fig-

ure 7C), triradiate mark not sharply delineated,

about 25-30 deep-set, 5 pm-wide areolae on each of

3 facets (Figures 6F, 7A, B). Chromosome number n

= 8 (Bornefeld 1984) (Figure 5G).

Under adverse conditions small perennating bul-

bils, which enable the plant to survive, are formed

from the apices of the thalli.

R. microciliata has a wide distribution in the

warmer summer rainfall areas, but is not often col-

lected as it is easily overlooked and may be mistaken

for a minor form of R. trichocarpa-, it is even smaller

than R. pottsiana Sim, which Sim described as ‘the

smallest Riccia known to me’. It is distinguished

from other southern African members of the ‘Cilia-

174

Bothalia 16,2 (1986)

FIGURE 5. — Riccia microciliata ( S . M. Perold 751 , PRE). Structure of thallus, cilia and chromosomes. A, parts of a rosette (cilia

only partly drawn); B, dry, living thallus (cilia again only partly drawn); C, ventral surface of lobe, flanks dark in upper part;

D, transverse section of lobe with young sporangium; E, epithelial cells from above; F, cilium with sides inflexed; G, chromo-

somes. (A-F by O. H. Volk; G, by T. Bornefeld. Drawings by G. Condy.) Scale bars on A-C = 1 mm; D = 200 pm; E = 100

pm; F = 50 pm; G = 1 pm).

Bothalia 16,2 (1986)

175

tae’ group, by being much smaller and by its arched,

deeply channelled, striate cilia; R. trichocarpa Howe

(= R. canescens Steph., Jovet-Ast (1983)) is about

twice as large, and has long, straight, pointed cilia;

R. crozalsii Lev. is confined to the wetter regions of

the south-western Cape and is also larger, with a

more delicate texture and granulate cilia; R. natalen-

sis is 10-12 mm long and about 4-8 times broader

than high, with wide triangular cilia and R. mammi-

fera sp. nov. has enlarged marginal cells up to 150

pm long.

R. warnstorfii Limp. (— R. commutata Jack.)

sometimes develops cilia (Paton 1980), but is not

usually treated under the ‘Ciliatae’ although Ste-

phani (1898) did so. It was probably introduced to

South Africa as it was only collected in Lilian’s Rose-

bank (Cape) garden by Garside 6648, 6649 (BOL),

during May 1954 and not since or elsewhere. These

specimens were devoid of cilia.

R. microciliata is known from northern South

West Africa/Namibia, eastern Botswana, northern,

north-western, western, central and eastern Trans-

vaal and western Natal (Figure 4).

SPECIMENS EXAMINED

SWA/NAMIBIA. — 1918 (Grootfontein): Gaikos (-AD),

Volk 811130 (M, PRE); Volk 811131b (M).

FIGURE 6 — Riccia microciliata (5. M. Perold383, PRE). Thallus, cilia and spores. A, surface view; B, crowded

cilia; C, bulbous base of cilium; D, cilium with longitudinal striations; E, channelled cilium; F, prox. face of

spore. (A-E, SEM micrographs; F, LM (light microscope) by S. M. Perold). Scale bars on A-E = 50 pm;

diameter of spore on F ± 90 pm.

176

Bothalia 16,2 (1986)

FIGURE 7. — Riccia microciliata (S. M. Perold 102 , 383 , PRE). Spores. A, proximal face; B, viewed from side;

C, apex; D, marginal pore; E, F, distal face. (SEM micrographs by S. M. Perold). Scale bars = 50 pm.

BOTSWANA. — 2127 (Francistown): NE-District between

Shashi River and Francistown, Long 12434 (E, M).

TRANSVAAL. — 2228 (Maasstroom): Alldays, 27 km NW of

(-DB), 5. M. Perold 748a; 751 (PRE). 2327 (Ellisras): Her-

mansdal, N of Stockpoort (-BC), Smook 4267 (d) (PRE). 2330

(Tzaneen): Lebowa, Ga-Modadji (-AD), Glen 1405(a) (PRE);

Letsitele (-CD), Glen 1411 (PRE). 2331 (Phalaborwa): Silongwe,

Plot 2 (-CC), /. M. Relief 252 (PRE). 2428 (Nylstroom): Doorn-

draai Nat. Res., 35 km NNW of Naboomspruit (-BD), S. M. Per-

old 435 (PRE); Loubad, NW of Nylstroom (-CA), 5. M. Perold

818 (PRE). 2527 (Rustenburg): 62 km N of Rustenburg, on road

to Northam (-AB), S. M. Perold 243 (PRE); Volk 81/249 (M,

PRE). 2529 (Witbank): Farm Bankfontein, 20 km N of Middel-

burg, Cycad Trail (-CB), 5. M. Perold 102 (PRE). 2530 (Lyden-

burg): near Marmerkop Sta., at turnoff to Boschhoek (-AB),

S. M. Perold 426(b) (PRE); Farm Winkelhaak, 5 km from Badplaas

on road to Lochiel (-DC), S. M. Perold 1026 (PRE). Grid refer-

ence unknown: Limpopo River, Farm Breslau, Vogel T465 (M,

PRE).

NATAL. — 2829 (Harrismith): Tugela River bank, at entrance

to Royal Nat. Park (-DB), 5. M. Perold 308 (PRE).

3. Riccia mammifera Volk & Perold , sp. nov.

Monoica, perennis; frondes mediocres, ad 10 mm

longae, ad 3 mm latae, 3- ad 4-plo latiorae quam

crassae, obcuneatae, 2- ad 3-plo furcatae, dorsaliter

late canaliculatae, marginibus tumidibus, ciliis par-

vis, ad 150 pm longis, apicaliter acervatis, in rosulis

ad 250 mm latis. Epithelium dorsalis unistratosum,

pro parte majore cellulis distinctissimis mammillatis

— inde nomen — ciliisque sparsim interspersis com-

Bothalia 16,2 (1986)

177

FIGURE 8. — Riccia mammifera (5. M. Perold 447 , PRE). Structure of thallus, cells, spores and chromosomes. A, fresh thallus; B,

dry thallus with sporangia; C, transverse section of lobe near apex; D, transverse section of older part of lobe, E, F, mammil-

late epithelial cells; G, short cilium at margin; H, marginal row of short cilia; I, epithelial cells from above; J, distal face of

spore; K, single areola with raised tubercles at nodes, x 1 500; L, spore from the side; M, proximal face of spore; N, chromo-

somes. ( A-M by O. H. Volk; N by T. Bornefeld. Drawings by G. Condy.) Scale bars on A, B = 2 mm; C, D = 1 mm; E-G =

50 pm; H, I = 100 pm; J, L, M = 50 pm; N = 1 pm.

178

Bothalia 16,2 (1986)

FIGURE 9. — Riccia mammifera (5. M. Perold 44, PRE). Thallus, cells and spore. A, surface view; B, cilia and

scales along margin; C, 2 short cilia (or enlarged marginal cells); D, proximal face of spore. (A-C, SEM

micrographs; D, LM (light microscope) by S. M. Perold). Scale bars on A-C = 50 pm; diameter of spore on

D ± 100 pm.

positum. Squamae inconspicuae, evanescentes. Spo-

rae 80-115 pm diametro, stramineae, trianguloso-

subglobosae, polares, alatae, laxe reticulatim lamel-

latae, 8-12 areolis in diametro, papillis angularibus

distinctis. Chromosomatum numerus n = 9 (Borne-

feld 1984).

TYPES. — Transvaal, 2529 (Witbank): Farm

Klipfontein, Distr. Verena, 24 km E of Bronk-

horstspruit/Groblersdal road, on dirt road to Sus-

terstroom, near small streamlet, tributary of Wilge-

rivier (-CA), 1984.05.27, 5. M. Perold 447 (PRE,

holo.), associated with Anthoceros and Campylopus

species and clumps of grass, soil pH 5,9; 1983.12.12,

F. Wagener CH 45 1L^

Thallus monoicous, perennial, green, in complete

or incomplete rosettes, up to 250 mm across,

medium-sized; branches 2 or 3 times furcate, nar-

rowly divergent (Figure 8A), (5-) 7-10 x 1-3 mm,

3-4 times broader than thick, obcuneate or oblong,

rarely linear; apex usually broadest, truncate or

rounded, emarginate; upper surface broadly

grooved to nearly flat (Figure 9A), margins tumid,

raised and rounded, slightly attenuate and overhang-

ing; flanks sloping obliquely up and outwards (Fig-

ures 8C & D), violet towards the apex, otherwise

green; ventral surface rounded to flat, green; when

dry, dorsal surface pale green, whitish in older parts,

apex and sides inflexed over short, deep sulcus (Fig-

ure 8B). Cilia in the form of enlarged marginal cells,

only conspicuous at margins of apical parts (Figures

8G & H, 9B), usually absent from older proximal

margins, vertical or slanting (Figure 8G), tips

rounded to pointed, thin-walled, smooth, up to 150

pm long and 60 pm wide at base (Figure 9C). Ana-

tomy of thallus: cells of dorsal epithelium in one layer

(Figures 8E & F), hyaline, size variable, 30-50 x 50

pm, upper wall dome-shaped or with small central

nipple (mammillate); air-pores 3-5-sided, mostly 4-

sided (Figure 81); in section assimilation tissue (chlo-

renchyma) occupying about \ the thickness of thal-

lus, cells isodiametric, about 25 pm wide, in closely

packed vertical columns of 8-10 cells, enclosing nar-

row air-canals; storage tissue with cells of variable

size, up to 60 pm wide; rhizoids hyaline, mostly

smooth, up to 30 pm wide. Scales small and incon-

spicuous, not reaching margin of thallus (Figure 9B),

225 x 315 pm, dark violet and shiny at apex, margins

hyaline, proximally entirely hyaline or lost, cells 5-

sided, about 50 x 45 pm in size, smaller at margin,

cell walls straight. Antheridia with ostioles project-

ing about 160 pm. Archegonia along midline, necks

purple and tips hyaline. Sporangia crowded in

groups of up to 6 per lobe (Figure 8B), bulging dor-

sally, overlying tissue often purple, containing

220-270 spores each. Spores 85-115 pm in diameter,

triangular-globular, polar, straw-coloured to brown,

semi-transparent, with wing about 5 pm wide, at

Bothalia 16,2 (1986)

179

FIGURE 10. — Riccia mammifera ( S . M. Perold 447, PRE). Spores. A, B, proximal face; C, apex and edge; D,

viewed from side with pore showing; E, distal face; F, areolae on distal face. (SEM micrographs by S. M.

Perold). Scale bars = 50 pm.

marginal angles up to 10 pm wide, notched or with a

pore (Figures 8L, 10D), margin slightly sinuate and

nearly smooth (Figure 10C); distal face reticulate,

with thin ridges forming 8-12 areolae across di-

ameter (Figures 8J, 10E), mostly hexagonal (Figure

10F), about 10 pm wide, with raised tubercles at the

nodes (Figure 8K); proximal face rather flattish (Fig-

ures 8L, 9D), triradiate mark present, not conspicu-

ous to prominent (Figure 8M), facets reticulate with

about 25 areolae, or with irregular, vermiculate

ridges; in side-view (Figure 8L) with low, truncate

papillae. Chromosome number n = 9 (Bornefeld

1984) (Figure 8N).

This rare species has been collected only twice. It

grows on the banks of small streams, in the north-

western and central Transvaal, on temporarily wet,

clayey soil, shaded during part of the day. (Figure

4).'

Originally it was suspected that R. mammifera and

R. coronata Sim might be synonymous. The type and

only specimen of R. coronata ( Sim 8730 , from Mooi

River, Natal) has been lost. Arnell (1963) mista-

kenly described the Duthie 5004 (BOL) specimen of

R. alatospora (see Volk & Perold 1985) as R. coro-

nata. According to Sim's diagnosis R. coronata , has

‘scales fairly large, horizontal when moist', and the

row of long white mammillate cells (cilia) would

probably be up to about 450 pm long, judging by the

180

Bothalia 16,2 (1986)

dimensions of the thallus in Sim’s drawing and those

given in the text. R. mammifera , on the other hand,

has small inconspicuous, evanescent scales, and the

marginal cells are only up to 150 pm long; other par-

ticulars in Sim’s description are too meagre. R.

mammifera has therefore been described as a new

species and is distinguished from other ciliate south-

ern African species by the broad thallus, by the short

wide, non-canaliculate cilia, and by the spore orna-

mentation on the distal face, consisting of mostly

hexagonal areolae with raised tubercles at the nodes.

R. mammifera with enlarged cells (or short cilia)

along the thallus margins has here been treated as a

member of the ‘Ciliatae’ group.

Pande & Udar (1958) reported small cilia,

100-150 pm long at the margins and on the surface of

the thallus in R. melanospora Kash., a character also

present in R. atromarginata Lev., but rarely encoun-

tered, and certainly not previously seen in a south-

ern African species.

SPECIMENS EXAMINED

Besides the type and paratype collections, R.

mammifera is so far only known from the following

locality:

TRANSVAAL. — 2328 (Baltimore): near Melkrivier, 51 km

NE of Vaalwater, at old bridge over Palala River (-CD), S. M.

Perold 841 (PRE).

ACKNOWLEDGEMENTS

The authors wish to thank Dr habil. T. Bornefeld,

Am Reelein 1, D-8706, Hochberg, Germany for the

chromosome counts and figures. Thanks are also

due to the late Prof. E. A. Schelpe, Bolus Herbar-

ium, University of Cape Town, for the loan of the

type specimen of R. natalensis and to Miss L.

Smook, Mr G. Germishuizen and Mr F. Wagener

for collecting specimens.

REFERENCES

ARNELL, S. 1963. Hepaticae of South Africa. Swedish National

Scientific Research Council, Stockholm.

BORNEFELD, T. 1984. Chromosomenanalyse der Gattung Ric-

cia von Slid- und SW-Afrika und allgemeine Bemerkungen

zur Zytogenetik der Lebermoose. Nova Hedwigia 40:

313-328.

JOVET-AST, S. 1983. Riccia trichocarpa Howe et Riccia canes-

cens Steph. Cryptogamie, Bryologique et Lichenologique 4:

37^46.

NA-THALANG, O. 1980. A revision of the genus Riccia (Hepa-

ticae) in Australia. Brunonia 3: 61-140.

PANDE, S. K. & UDAR, R. 1958. Genus Riccia in India — II.

Proceedings of the National Institute of Science, India 24:

79-88.

PATON, J. A. 1980. Observations on Riccia bifurca Hoffm. and

other species of Riccia L. in the British Isles. Journal of

Bryology 11: 1-6.

RAUH, W. & BUCHLOH, G. 1961. Riccia crinita Taylor und

Riccia atromarginata Lev. Revue Bryologique et Lichenolo-

gique 30: 260-262.

SIM, T.R. 1926. The Bryophyta of South Africa. Transactions of

the Royal Society of South Africa 15.

STEPHANI, F. 1898. Species Hepaticarum. Bulletin de I'Herbier

Boissier 6: 309—411.

VOLK, O. H. 1983. Vorschlag fur eine Neugliederung der Gat-

tung Riccia L. Mitteilungen aus der Botanischen

Staatssammlung, Munchen 19: 453^465.

VOLK, O. H. & PEROLD, S. M. 1985. Studies in the genus Ric-

cia (Marchantiales) from southern Africa. 1. Two new

species of the section Pilifer: R. duthieae and R. alato-

spora. Bothalia 15: 531-539.

Bothalia 16,2: 181-185 (1986)

Studies in the genus Riccia (Marchantiales) from southern Africa. 5.

R. rosea , a new species

O.H. VOLK* and S.M. PEROLD**

Keywords: Marchantiales, Riccia rosea, species nova, southern Africa, ‘Squamatae’, taxonomy

ABSTRACT

A new species of Riccia, R. rosea Volk & Perold of the group Squamatae’, section Riccia, subgenus Riccia, is

described. It is endemic to southern Africa and is characterized by large ventral scales with hyaline margins and

reddish pink to deep rose-pink bases, and by the light green dorsal colour of the thallus, fading to white along the

margins and older parts. Fertile male plants have prominent hyaline ostioles. The spores are globular or subglobu-

lar and apolar, with 9-11 well defined areolae across the diameter.

U1TTREKSEL

’n Nuwe endemiese spesie van Riccia, R. rosea, wat behoort tot die groep ‘Squamatae’, seksie Riccia, subgenus

Riccia, word beskryf. Die spesie word gekenmerk deur groot pienk ventrale skubbe met kleurlose rande, die

liggroen dorsale oppervlak van die tallus, en anteridie met opvallende ostiole. Die spore is bolvormig of amper

bolvormig en apoler, met 9-11 duidelike areole in die deursnee van die spoor.

Riccia rosea Volk & Perold, sp. nov. squamis

grandibus, marginis hyalinis, basiliter pluricoloratis,

colore dorsali pallide-viridi ceteris speciebus gregis

Squamatae differt.

Thallus dioicus, perennis, mediocris ad magnus,

pallide-viridis. Frons ad 12 mm longa, 1,0 ad 2,5 mm

lata, 1,0 mm crassa, simplex ad asymmetrice pluri-

furcata, segmenta 2,0 ad 4,0 mm longa, marginibus

acutis, lateribus rectis ad obliquis, apicem versus

acute vel subacute sulcata. Squamae prominentes,

marginem frondis superantes, in sicco superficie

frondis tegentes, marginibus hyalinis irregularibus

basaliter pluricoloratae, subpurpureae, lateritiae et

roseae, inde nomen. Ostiola prominentes. Sporae

magnae, globosae, apolares, reticulatae. Chromoso-

matum numerus n = 8 (Bornefeld 1984).

TYPES. — Transvaal, 2528 (Pretoria): Farm

Valschspruit, 19 km N of Bronkhorstspruit, on soil

at base of weathered granitic rocks, on hilltop

(-DB), 1982.02.20, S.M. Perold 324 (PRE, holo.);

1980.12.01 Volk 811023 (M, PRE), associated with

Myrothamnus flabellifolia, Selaginella dregei, R.

atropurpurea Sim and R. okahandjana S. Arnell.

Soil pH 5,8 and 6,2.

Thallus dioicous, perennial, in crowded gregari-

ous patches or scattered; simple or once to twice

symmetrically or asymmetrically furcate, branches

diverging 45°-60°, ligulate, narrow proximally, up to

12,0 mm long, 1, 0-2,5 mm broad, 1,0-2, 5 times

broader than thick, segments 2 ,0-4,0 mm long; apex

rounded, shortly emarginate, sulcus narrow and

deep, becoming shallow proximally (Figures IB &

C, 2A & B), dorsally light green, white at margins

and older parts; margins acute, flanks steep to as-

cending obliquely near the apex, reddish pink; ven-

* Botanische Anstalten d. Univ. Wurzburg D 8700, Germany,

BRD.

** Botanical Research Institute, Department of Agriculture &

Water Supply, Private Bag X101, Pretoria 0001, RSA.

tral surface rounded, green, often with narrow violet

transverse bands; when dry, dorsal surface white to

greenish white, apex and sides inflexed (Figure 1A),

covered by prominent scales. Anatomy of thallus'.

cells of dorsal epithelium hyaline, in one to two lay-

ers, globular to somewhat flattened above (Figure

2D), about 35 pm high x 35-55 pm wide, soon col-

lapsing and sunken, forming thick-walled ‘ring cells'

(Figures IF & H), air-pores mostly triangular (Fig-

ure 1H), margin of thallus with thick-walled (± 5

pm), irregularly shaped cells (Figure 1J); assimila-

tion tissue (chlorenchyma) about 1/2 the thickness of

thallus, cells short-rectangular, 60-70 x 40-50 pm,

in columns of 7 or 8 cells (Figure IF) enclosing nar-

row 3- or 4-sided air-canals (Figure 1G); storage tis-

sue nearly 1/2 the thickness of thallus, cells rounded,

about 55-60 pm wide, irregularly arranged; ventral

epidermal cells rectangular. Rhizoids hyaline,

smooth and tuberculate, 15-20 pm wide. Scales

closely imbricate, wavy, semi-circular, large (Figure

2C), 800-900 x 500-750 pm, projecting about 175

pm above thallus margin, reddish or rose-pink

(hence the specific epithet), with hyaline margins

1 -4 (-5) cells wide (Figure IK); apical scales some-

times almost entirely hyaline; cells 4-7-sided, 65-100

x 40-50 pm, cell walls straight (Figure II); marginal

cells smaller, about 25 x 30 pm; rhizoids sometimes

arising ventrally from scale margins. Antheridia with

large prominent hyaline ostioles about 370 pm tall,

in 1 or 2 rows along dorsal groove of male plants,

epithelium shrunken away around base of ostioles

(Figure IB). Archegonia scattered along median

part of female plants, necks purple. Sporangia: 3 or

4 dotted along length of lobe (Figure 1C), each con-

taining about 200 spores; dorsal surface bulging,

soon disintegrating, seldom developing purple

blotches; plants rarely fertile. Spores 92,5-105.0 pm

in diameter, light brown to brown, semi-transparent,

subglobular to globular, apolar, wing and triradiate

mark absent (Figure 3A & F), outline crenate or

bluntly papillose; ornamentation regularly reticulate

on all faces (Figure 3B & D), only distinguishable

FIGURE 1. — Riccia rosea (S. M. Perold 324, PRE). Structure of thallus, scales and chromosomes. A, dry thalli; B, fresh male

thalli with prominent ostioles; C, fresh female thallus with sporangia; D, transverse section of male thallus; E, transverse

section of female thallus towards proximal part; F, transverse section through chlorenchyma; G, horizontal section through

chlorenchyma showing air-canals; H, collapsed epithelial cells (‘ring'-cells) and air-pores from above; I, scale; J, marginal

cells of thallus; K, multi-coloured scale; L, chromosomes. (A-K by O. H. Volk; L by T. Bornefeld. Drawings by G. Condy.)

Scale bars A-E = 2,0 mm; F-I = 200 pm; J = 100 pm; K = 500 pm; L = 1 pm.

Bothalia 16,2 (1986)

183

from each other by occasional indentation in centre

of distal face (Figure 3C), 9-11 well defined,

rounded or angular areolae across diameter, each

areola about 10 pm wide, bordered by ridges up to

5,0 pm high, raised at nodes (Figures 3D & E).

Chromosome number n = 8 (Bornefeld 1984) (Fig-

ure 1L).

R. rosea can be recognized by the white dorsal sur-

face of the dry, and the older parts of the wet thallus,

which seldom develops any purple colouration; by

the prominent antheridial ostioles of male plants and

by the large scales which are irregularly wavy and

tightly appressed when dry. At the apex of the thal-

lus some scales are entirely hyaline; along the sides

of the thallus the scales have pink bases and more

proximally, the scale colour darkens to deeper rose-

pink or dark bluish red, flecked with groups of more

intensely stained cells. The outer 1-5 rows of cells at

the scale margins are usually hyaline and appear

thick-walled, sometimes with a bluish tint; the

deeper coloured cell groups in the body of the scale

are not sharply delimited as there is a gradual

shading in colour.

A few other species of Riccia with red or purple

scales also have subglobular spores; however, the

papillae at the nodes of the areolae of R. rosea

spores are intermediate in length between the very

prominent truncate projections of R. runssorensis

Steph. and the low turbercles of R. atropurpurea

Sim; the colour of the spores is also a distinguishing

character: R. rosea has light brown spores, whereas

R. runssorensis and R. atropurpurea have much

darker, red to black spores. R. rosea is a more robust

plant than R. atropurpurea, which has dull, very

deep purple or dark brown to almost black scales

with hyaline edges that do not extend above the thal-

lus margins; the thallus is glaucous gray dorsally and,

when dry, the sides are usually tightly inflexed with 2

white marginal lips running along the midline. More

difficult to distinguish from R. rosea is R. runssoren-

sis, which also has red scales, often with hyaline

edges, but they hardly extend beyond the thallus

margins; the thallus is bright green dorsally, the

lobes usually branching 2 or 3 times, and the dorsal

epidermal cells are mammillose, not globose. R.

rosea is the only one of the above three species that

is dioicous.

It grows in full sunlight, but can tolerate partial

shade, and often grows mixed with other Riccia

species e.g. R. okahandjana, R. atropurpurea and

moss species and with small annuals and/or perenni-

als like Craterostigma wilmsii, Lobelia nuda, Orope-

tium and Cyperus spp. R. rosea is sometimes found

growing on the rotting roots of grasses but it prefers

shallow sandy soil overlying granitic, quartzitic or

sandstone outcrops. Soil pH values range between

4,4 and 7,0. R. rosea is weakly acidophile to neutro-

phile; of 21 soil samples tested, the pH of 62% were

between 5,5 and 6,4; of 24% between 6,5 and 7,0

(Volk). It has a widespread distribution in the sum-

mer rainfall areas of southern Africa (annual rainfall

300-600 mm or more), where the habitats become

saturated with water for short intervals during the

FIGURE 2. — Riccia rosea (5. M. Perold 324, PRE). Structure of thallus and cells. A, surface view of thallus; B,

apex and groove; C, apical scales; D, dorsal cells. (SEM micrographs by S. M. Perold). Scale bars = 50 pm.

184

Bothalia 16,2 (1986)

FIGURE 3. — Riccia rosea (S. M. Perold 142, 344, PRE). Spores. A, proximal face; B, proximal side; C, distal

face; D, side; E, areolae; F, ? proximal face. A-E, SEM micrographs and F, LM (light microscope) by

S. M. Perold. Scale bars on A-E = 50 pm; diameter of spore on F = 100 pm.

rainy season, followed by long dry periods, which

the plants survive in a resting state. When it rains

again, even after several years, they revive quickly.

Riccia rosea has been recorded from South West

Africa/Namibia, Botswana, Transvaal and northern

Orange Free State. Figure 4.

ACKNOWLEDGEMENTS

The authors wish to thank Dr. habil. T. Borne-

feld, Am Reele 1, D-8706 Flochberg, Wurzburg,

Germany, for the chromosome counts and figures;

sincere thanks are due to Mrs D. M. C. Fourie and

Dr H. F. Glen, both of BRI, for kindly collecting

specimens of R. rosea.

REFERENCES

ARNELL, S. 1967. Hepaticae collected in South West Africa by

Prof. O. H. Volk. Mitteilungen aus der Botanischen Staats-

sammlung, Miinchen 16: 262-272.

BORNEFELD, T. 1984. Chromosomenanalyse der Gattung Ric-

cia von Slid- und SW-Afrika und allgemeine Bemerkungen

zur Zytogenetik der Lebermoose. Nova Hedwigia 40:

313-328.

NA-THALANG, O. 1980. A revision of the genus Riccia (Hepa-

ticae) in Australia. Brunonia 3: 61-140.

VOLK, O. H. 1983. Vorschlag fur eine Neugliederung der Gat-

tung Riccia L. Mitteilungen aus der Botanischen

Staatssamrnlung, Miinchen 19: 453-465.

VOLK, O. H. 1984. Pflanzenvergesellschaftungen mit Riccia- Ar-

ten in Siidwestafrika (Namibia). Vegetatio 55: 57-64.

VOLK, O. H. & LEIPPERT, H. 1971. Vegetationsverhaltnisse

im Windhoek Bergland, Sudwestafrika. SUM Wissen-

schaftliche Gesellschaft — Windhoek 25: 5 — 44.

Bothalia 16,2 (1986)

185

SPECIMENS EXAMINED

S.W. A. /NAMIBIA. — 1915 (Okaukuejo): OU 183 (ETO) Ot-

jowasandu, on granite, 1 250 m, 430 mm rain, (-DB), Volk 00930

(M, PRE). 1917 (Tsumeb): GR 605, Kamanjab, on sandy soil,

1 300 m, 550 mm rain, (-BA), Volk 811153 (M, PRE). 1918

(Grootfontein): GR 729 Gaikos, on quartzite, 1 150 m, ca 550

mm rain, (-AD), Volk 81/124 p.p., 81/125, 81/131, 81/132, 81/133,

841693, 841700 p.p., 84/701 p.p., 84/702 p.p., (M, PRE). 2016 (Ot-

jiwarongo): GR 83 Luckenwalde, on granite, 1 450 m, 450 mm

rain, (-BB), Volk 84/707 (M); OTJ 87 Lichtenau, at base of grani-

tic batholite, 1 500 m, 400 mm rain, (-CC), Volk 84/710 p.p. (M,

PRE). 2216 (Otjimbingwe): OM 37 Otjua, on granite, 1 4fXJ m,

350 mm rain, (-AA), Volk 81/106 (M, PRE), 81/111 (M), 81/116,

84/714, 841715, 84/716 (M, PRE). 2217 (Windhoek): WIN 83

Rietfontein, on granite, 1 775 m, 400 mm rain, Volk 01165 p.p.

(M); WIN 84 Tew, on granite, 1 750 m, 340 mm rain, (-CD),

Volk 81/270 (M). 2417 (Mariental): GIB 18 Haribes, on quartzite,

1 300 m, 200 mm rain, (-DA), Volk 12403 (M) (det. Arnell 1957,

as sub R. runssorensis). 2516 (Helmeringhausen): MAL84 Duwi-

sib, on quartzite, 1 550 m, 170 mm rain (-BC), Volk 6334 f.Mj.

BOTSWANA. — 2127 (Francistown): NE-District between

Shashi River and Francistown (A?), Long 12438 (E, M).

TRANSVAAL. — 2228 (Maasstroom): Tolwe, 16 km W of

(-CD), S. M. Perold 785 (PRE); Alldays, 27 km NW of (-DB), S.

M. Perold 749, 750, 753 (PRE). 2229 (Waterpoort): Farm Drie-

hoek (-DC), D. Fourie23c, 24c (PRE). 2330 (Tzaneen): Lebowa,

Ga-Modadji (-AD), Glen 1403b (PRE). 2430 (Pilgrim’s Rest):

Bourke’s Luck Potholes, 27 km N of Graskop (-DB), S. M. Per-

old 408 (PRE). 2527 (Rustenburg): Farm Beestekraal (-BC), 5.

M. Perold 881 (PRE). 2528 (Pretoria): Bronkhorstspruit, Farm

Valschspruit (-DB), 5. M. Perold 139-143; 322, 323 (PRE). 2529

(Witbank): Middelburg, 40 km N of (-CB), Volk 811020 (M,

PRE). 2629 (Bethal): Kriel, 5 km W of, on road to Vandyksdrift

(-AB), S. M. Perold 344, 346, 347 (PRE).

O.F.S. — 2727 (Kroonstad): Parys, 9 km S of on N1 road

(-AB), Volk 811031, 81/032 (M. PRE); 5. M. Perold 185, 196

(PRE). 2926 (Bloemfontein): 30 km S of Bloemfontein (-AC), S.

M. Perold 954 (PRE).

Bothalia 16,2: 187-191 (1986)

Studies in the genus Riccia (Marchantiales) from southern Africa. 6.

R. hirsuta , a new species, in a new section

O. H. VOLK* and S. M. PEROLD**

Keywords: anatomy, Marchantiales, Micantes sectio nova, Riccia hirsuta, species nova, southern Africa, taxonomy

ABSTRACT

Riccia hirsuta Volk & Perold, sp. nov., the type species of a new section, Micantes Volk & Perold, subgenus

Spongodes (Nees) Volk is described. It is characterized by tall, dorsal, hair-like, multi-cellular outgrowths from an

epidermis with distant air-pores, leading to polyhedral air-chambers below, and is the only species in this subgenus

with these outgrowths. The ventral scales are triangular, apically splitting into long, hair-like appendages. This

species is endemic to the north-west and central Cape Province.

UITTREKSEL

Riccia hirsuta Volk & Perold, sp. nov, die tipe spesie van die nuwe seksie Micantes Volk & Perold, subgenus

Spongodes (Nees) Volk word beskryf. Dit word gekenmerk deur lang, haaragtige, veelsellige, dorsale sel-pilare,

wat uitgroei van ’n epidermis onderbreek deur poriee wat lei tot poliedriese lugkamers benede en is die enigste

spesie in die subgenus met hierdie sellulere uitgroeisels. Die ventrale skubbe is driehoekig en apikaal verdeel in

lang, haaragtige aanhangsels. Die spesie is endemies tot die noordwestelike en sentrale Kaapprovinsie.

Micantes Volk & Perold , sect. nov. subgeneris

Spongodes generis Riccia. Thallus dorsaliter dense

obtectus pilis multicellularibus hyalinis, micantibus

(inde nomen).

TYPE. — Riccia hirsuta Volk & Perold, sp.

nov.

Thallus dorsally densely covered with multicellu-

lar, hair-like, hyaline, shiny (hence the name) pil-

lars. In the subgenus Spongodes no other section has

these tall dorsal hairs.

Riccia hirsuta Volk & Perold , sp. nov.

Frons usque ad 15 mm longa, 2-5 mm lata, duplo

ad triplo latior quam crassa, simplex vel furcata, ob-

cuneata vel oblonga, apice breviter emarginata, sub

apice canaliculata, antice subplana, ab pilis multicel-

lularibus quasihirsuta (inde nomen speciei), margini-

bus plus minus attenuatis; costa lata, crassa, sub-

plana vel convexa, ad margines sensim excurrens.

Stratum aeriferum cavernis altis. Squamae grandes,

marginem frondis superantes, imbricatae, hyalinae,

deltatae, apicibus in filis liberis scissis. Sporae tri-

angulo-globulares, polares, brunneae, 115-125 pm

diametro, late alatae, margine subtiliter crenato, ir-

regulariter reticulatae, areolae centrales magnae, ad

25-38 pm latae, areolae marginales parviores. Chro-

mosomatum numerus n = 8 (Bornefeld 1984).

TYPE. — Cape, 3018 (Kamiesberg): Kamies-

berg plateau, north of Leliefontein, towards Draai-

klip, on sandy, periodically moist soil (-AC),

1983/09/06 Oliver 8040 (PRE, holo.), associated with

other Riccia species and Restionaceae. Soil pH 5,3.

* Botanische Anstalten d. Univ. Wurzburg D 8700, Germany,

BRD.

* ‘Botanical Research Institute, Department of Agriculture and

Water Supply, Private Bag X 101, Pretoria 0001, RSA.

Thallus monoicous (?), perennial, scattered or in

incomplete rosettes, dorsally furry, whitish along

margins, greenish grey over centre; medium-sized to

large (Figure 1 A, B); simple or bifurcate, lobes up to

15 mm long, 2, 0-4,0 (-5,0) mm broad, 1, 5-2,0 mm

thick, i.e. about two to three times broader than

thick; oblong, obcordate when young (Figure IB),

broadening towards rounded to truncate, emargi-

nate apex; groove short, obscured by thick pelt of

shiny hairs, dorsal surface soon becoming flat; mar-

gins subacute to slightly tumid; flanks steep to slop-

ing outwards in a short wing (Figure 1C1? C2, C3),

greyish green, occasionally with some reddish purple

flecks; ventral surface slightly rounded to plane, pale

green; when dry, sides partly indexed, dorsal surface

grey, dusty from accumulation of sand grains trap-

ped between collapsed hairs. Anatomy, dorsal cov-

ering of loose, hyaline, straight to bent, hair-like cell

pillars (Figure 2A, B), up to 1 500 pm long, occupy-

ing up to nearly \ the thickness of frond (Figures

lCj, C2, C3, 2C), consisting of one to seven thin-

walled cells (Figures ID, 2D), 50-200 x 35-120 pm,

tapering to apex (Table 1), distances separating

bases of hairs ± 15-120 pm; epidermis between hairs

consisting of flat to slightly bulging, polygonal cells

(Figures 2G, H) 40-65 (-80) x 30-40 (-50) pm and

about 20 pm high, sometimes slightly raised around

base of hairs; air-pores rectangular or five-sided, up

to 20 pm wide, formed between 4 or 5 surrounding

cells, distances between pores about 50-250 pm (Fig-

ure 2G, H); assimilation tissue (chlorenchyma)

about 500-600 pm thick, almost 3 the thickness of

frond (Figures 1C1? C2, C3, 2C) with tall, polyhedral

air-chambers (Figures ID, 2D, E) 65-100 pm wide,

sloping obliquely and gradually becoming almost

vertical near surface, enclosed by four to six plates,

one cell thick, cells 35-65 x 33-45 pm; storage tissue

about 500 pm thick, consisting of irregularly ar-

ranged, polygonal cells, up to 50 pm wide, in older

188

Bothalia 16,2 (1986)

FIGURE 1. — Riccia hirsuta (Oliver 8040, 8038a, Schelpe 7784). Morphology and anatomy. A, dry thallus with sporangia; B,

freshly regenerating young thalli; C,, C2, transverse sections of lobe; C3, transverse section through lobe of dormant thallus,

only shaded part living and filled with storage material, other parts emptied and dead; D, hairs of dorsal cover; E,, scale; E2,

E3, top part of scales; F[, F2, F3, F4, tips of scales divided into cellular strings, variously shaped and bent; G, ornamentation

on distal face of spore; H, chromosomes. (A-G by O.H. Volk; H by T. Bornefeld. Drawings by G. Condy.) Scale bars: A, B,

C = 1 mm; D-F = 100 pm; G spore diameter ± 120 pm; H = 1 pm.

Bothalia 16,2 (1986)

189

FIGURE 2. — Riccia hirsuta (Le Roux & Fourie CH4494). Morphology and anatomy. A, dorsal view of thal-

lus; B, hair pillars; C, transverse section of lobe; D, transverse section showing top part of air-chamber

and base of hairs; E, chlorenchyma and air-chamber; F, scale; G, H, epidermis and air-pores. (SEM

micrographs by S.M. Perold). Scale bars on A-H = 100 pm.

190

Bothalia 16,2 (1986)

FIGURE 3. — Riccia hirsuta (Oliver 8040). Spores. A, proximal face; B, facet and pore on proximal face; C, distal

face; D, oblique view of distal face; E, pore at marginal angle; F, distal face. (A-E, SEM micrographs; and

F, LM (light microscope) by S.M. Perold). Scale bars on A-E = 50 pm; diameter of spore on F± 120 pm.

parts of thallus, on transverse section (Figure 1C3), a

central lenticular core is seen, where the storage

cells are densely filled with fatty oil or starch, the

surrounding layers of cells partially empty; rhizoids

arising from ventral epidermis and base of scales,

hyaline, smooth and tuberculate mixed, up to 25 pm

wide. Scales large, shaggy, partly extending above

margin of thallus, overlapping apically, triangular

(Figure 1E2, E3,), about 650 pm wide at base and up

to 1 500 pm high, hyaline, occasionally with reddish

purple cells at base; cells at base small (Figure lEj),

larger in body of scale and about 150 x 50 pm, ob-

long-hexagonal, marginal row of cells long-rectangu-

lar, cell walls thin, straight, toward apex cells elon-

gated to ± 190 pm and split up into several loose

strands of about four cells (Figure lF^, variously

bending and twisting (Figure IF-,, F3, F4). Antheridia

with tall hyaline ostioles, irregularly distributed, hid-

den by dorsal pillars. Archegonia with purple necks.

Sporangia arranged across width of thallus, up to 700

pm wide, overlying epidermis tinged with purple,

containing about 650 spores. Spores triangular-glo-

bular, polar, deep dull brown to nearly black, semi-

transparent to opaque, (95-) 115-125 (-130) pm in

diameter, with wing about 10 pm wide (Figure 3F),

slightly undulating, crenulate to somewhat eroded,

at angles with a pore or notched (Figure 1G, 3E);

distal face reticulate, with 3-5 (-6) large central

areolae, 25-38 pm wide, completely or incompletely

subdivided into smaller areolae, about 12,5 pm

Bothalia 16,2 (1986)

191

FIGURE 4. — Distribution map of Riccia hirsuta in southern

Africa.

TABLE 1. — R. hirsuta, size (in pm) of the cells of the dorsal

hair-pillars and cells of the chlorenchyma on transverse

section (Schelpe 7784)

Ratio

Average size Length Variation in size

wide, often with a papilla in the middle (Figure 3C,

D), occasionally areolae equally wide and then 8-10

across diameter; central ridges thick and high, outer

ridges thinner and lower, sometimes extending part-

ly onto wing; proximal face with triradiate mark dis-

tinct, but poorly delineated, each facet irregularly

and rarely completely reticulated (Figure 3A, B).

Chromosome number n = 8 (Bornefeld 1984) (Fig-

ure 1H).

R. hirsuta is endemic to, and rare in the north-

western Cape Province (Figure 4). It grows

on sandy, acid soil and may be associated with

other Riccia species, e.g. R. parvo-areolata Volk &

Perold, R. bullosa Link, R. schelpei Volk & Perold,

R. cupulifera A. V. Duthie, and sometimes with

small shrublets such as Ruschia robusta L. Bol., and

members of the Restionaceae.

The tall dorsal hair-like cell pillars have not pre-

viously been found in any species of the subgenus

Spongodes (Nees, pro sectio) Volk ( Ricciella auct.,

non A. Braun) (Volk 1983). They form an interest-

ing parallel development to the pillars in the section

Pilifer Volk (1983), subgenus Riccia , where, how-

ever, all the columns of the assimilation tissue con-

tinue into loose hyaline pillars and the air-pores are

formed by small interstices between rounded,

densely packed, hyaline cells.

R. hirsuta differs from all the known southern

African species of Riccia in the unique dorsal, hair-

like outgrowths from many of the epidermal cells

and the large ± triangular scales, apically splitting

into hair-like appendages. It is the type species of

the new section, Micantes , so named because of the

glistening dorsal covering.

CAPE. — 2917 (Springbok): Hester Malan Res., Carolusberg

N, at gate on western boundary (-DB), 1983/08/30, Le Roux &

Fourie CH 4494 (PRE); 1977/09/14, Schelpe 7784 (BOL, PRE).

3017 (Hondeklipbaai): Nuwefontein (-DD), 1951/1952, Vogel

C5446 (MJG). 3018 (Kamiesberg): Kamiesberg plateau, north of

Leliefontein, towards Draaiklip (-AC), 1983/09/06, Oliver 8038a

(M).

ACKNOWLEDGEMENTS

The authors wish to thank the late Prof. E.A.

Schelpe, of BOL, University of Cape Town, for the

loan of his specimen. Sincere thanks are also due to

Miss A. le Roux of the Department of Nature Con-

servation of the Cape Province and to Mrs D.M.C.

Fourie (PRE), as well as to Mr E.G.H. Oliver, Stel-

lenbosch, for collecting specimens. We gratefully ac-

knowledge the chromosome counts and figures by

Dr habil. T. Bornefeld, Am Reele 1, D-8706

Hochberg, Wurzburg, Germany.

REFERENCES

BORNEFELD, T. 1984. Chromosomenanalyse der Gattung Ric-

cia von Slid- und SW-Afrika und allgemeine Bemerkungen

zur Zytogenetik der Lebermoose. Nova Hedwigia 40:

313-328.

VOLK, O.H. 1983. Vorschlag fur eine Neugliederung der Gat-

tung Riccia L. Mitteilungen aus der Botanischen Staats-

sammlung , Munchen 19: 453-465.

Bothalia 16,2: 193-201 (1986)

Studies in the genus Riccia (Marchantiales) from southern Africa. 7.

R . congoana and its synonyms

S. M. PEROLD*

Keywords: Africa, Marchantiales, Riccia congoana, spores, synonymy, taxonomy

ABSTRACT

R. congoana Steph. is described and illustrated. R. rhodesiae S. Arnell, R. nigrosquamata E. W. Jones and R.

aegyptiaca S. Arnell are treated as synonyms under R. congoana. R. congoana has a wide distribution in Africa,

ranging from Egypt in the north to SWA/Namibia and Transvaal in the south, and from Sierra Leone in the west to

Tanzania in the east.

UITTREKSEL

R. congoana Steph. word beskryf en gei'llustreer. R. rhodesiae S. Arnell, R. nigrosquamata E. W. Jones en R.

aegyptiaca S. Arnell word as sinonieme van R. congoana beskou. Die verspreiding van R. congoana in Afrika strek

vanaf Egipte in die noorde, tot SWA/Namibie en Transvaal in die suide, en van Sierra Leone in die weste tot

Tanzanie in die ooste.

Riccia congoana Steph. in Bulletin de l’Herbier

Boissier 6: 20 (1898); E. W. Jones: 226 (1957). Type:

French Equatorial Africa, Foret de Ceseles, M. de

F. Vozs.n. sub G13336 (G-herb. Steph., ex hb. Bes-

cherelle, holo.!).

R. rhodesiae S. Arnell: 313 (1952); S. Arnell: 29 (1963a). Type:

S. Rhodesia [Zimbabwe], Victoria Falls, on soil near Trolley

Junction, Arnell 1291 (S, holo.!; BOL!, PRE!).

R. nigrosquamata E. W. Jones: 222 (1957). Type: Tanganyika

[Tanzania], Lighthouse Island, Dar-es-Salaam Harbour, Jones

699 (BM, holo.; Herb. Jones!).

R. berriei E. W. Jones: 224 (1957). Type: Nigeria, St. Anne’s

Churchyard, Kudeti, Ibadan, Berrie 1956 [not seen but placed in

synonymy under R. nigrosquamata by Berrie (1975)].

R. aegyptiaca S. Arnell: 9 (1963b). Type: Egypt (Egyptian-Su-

danese border), Gebl. Elba Distr., Wadi Aideib, M. Kassas s.n.

(S, holo.!).

R. limbatoides, nom. prov., O.H. Volk: 58 (1984). South West

Africa/Namibia, Grootfontein, Farm Gaikos, Volk 00747 (M,

PRE!).

Thallus monoicous,** perennial, scattered or in ir-

regular, partial rosettes 25,0-30,0 mm across, dor-

sally bright green to bluish or greyish green, reticu-

late, occasionally with irregular, white patches,

black scales forming a narrow scalloped border;

once or twice furcate, branches narrowly to widely

divergent (Figures 1A & B; 2A), almost equally long

or one branch occasionally longer, usually large to

very large, with older parts dead, lobes 6,0-12,0

(-15,0) x (2,0-) 3 ,0-4,0 (-5,0) mm, (0,65-) 0,75-0,90

(-1,0) mm thick, i.e. about three to five times

broader than thick; oblong or obovate, narrower

proximally; apex rounded, obtuse, slightly emargi-

nate; sulcus narrow and deep apically, with convex

sides, proximally shallow to flat (Figure lE^ E, &

* Botanical Research Institute, Department of Agriculture and

Water Supply, Private Bag X101, Pretoria 0001, RSA.

** Volk 00747 (R. limbatoides nom. prov.) is stated to be dioi-

cous by Volk (pers. comm.); Stephani reported R. congoana as

dioicous, but it definitely is monoicous; Jones describes R. ni-

grosquamata as monoicous, and so is 5. M. Perold 394.

E3); pitted around bases of antheridia; margins

acute, flanks sloping obliquely up and outward, atte-

nuate; ventral surface green, slightly rounded to

convex; when dry (Figure ID), margins inflexed

with large, shiny black or deep reddish purple scales

usually meeting along the middle and covering all, or

most of the dorsal surface. Anatomy of thallus: dor-

sal epithelium unistratose, cells globose or dome-'

shaped (Figures IF & G; 2D), about 30,0-35,00 pm

wide, thin-walled, upper wall soon collapsing, air-

pores in between cells mostly four-sided (Figure

1G); assimilation tissue (chlorenchyma) (Figure 1E15

E, & E,) nearly half the thickness of thallus, consist-

ing of vertical columns 6-8 cells high, columns

shorter towards margins, cells 45,0-55,0 pm high x

35,0-45,0 pm wide, enclosing narrow, usually 4-

sided air-canals (Figure IF); storage tissue about

half the thickness of thallus, cells angular to round,

thin-walled, variable in size, many also containing

chloroplasts; ventral epidermis giving rise to smooth

and tuberculate rhizoids. Scales large and conspicu-

ous, borne mostly on ventral side of wings of thallus

(Figure 1C), imbricate, stiff, black or deep purple-

red, shiny and sometimes duller, crescent-shaped to

rounded, 750-900 x ± 800 pm, projecting about

200-250 pm beyond thallus margins and partly ad-

herent to margin (Figure 2B & C), base often hya-

line; cells in body of scale long-rectangular, or 5-6-

sided, 75,0-85,0 x 25,0-50,0 pm, walls straight (Fig-

ures lHj & 1H,); margin of scales sometimes crenate

(Figure 1H,), with smaller cells; peripheral cell wall

often dipping in middle, higher at anticlinal walls,

forming so-called ‘saddle cells’ (O.H. Volk, pers.

comm.). Antheridia in one to two rows along sulcus,

prominent, projecting up to 250 pm, hyaline, bases

sometimes tinged reddish pink. Archegonia scat-

tered along groove, necks purple. Sporangia t single,

t Few of the southern African specimens had sporangia, but Ber-

rie (1975) reported the plants from Sierra Leone to be abundantly

fertile. E. W. Jones (pers. comm.) states that in Ibadan, R. ni-

grosquamata specimens were also fertile.

194

Bothalia 16,2 (1986)

FIGURE 1.— Riccia congoana (Smook 5139, PRE). Structure of thallus and scales. A, habit; B, dorsal view of wet thallus; C,

ventral view of wet thallus; D, dorsal view of dry thallus; E, transverse sections through lobe at different distances from the

apex: 1, near apex; 2, in middle; 3, towards base; F, globose epithelial cells; G, dorsal epithelium and air-pores from above;

FI,, scale; H:, margin of scale; I, chromosomes. [Illustrations A-FI, by G. Condy, I, by T. Bornefeld on Volk 00747 (under

R. limbatoides nom. prov.)]. Scale bars on A = 2 mm; B-E = 1 mm; F, G = 50 pm; H = 100 pm; I = 1 pm.

Bothalia 16,2 (1986)

195

or several along groove, bulging dorsally, overlying

tissue disintegrating and spores lying free in long,

broad hollows or ‘pits’, (Berrie 1975); ± 250-300

spores contained in each sporangium. Spores subglo-

bular, rarely subtriangular-globular, usually apolar,

without wing and triradiate mark, diameter (80-)

100-130 (-135) pm, yellowish brown to reddish

brown, semi-transparent, surface granular (under

light microscope), regularly reticulated* with 6-8

(-10) angular areolae across diameter of spore (Fig-

ure 3A, B, C & D), areolae 10,0-15,0 (-17,5) pm

wide, borders usually thin and delicate, with faint

striations, tall, 4, 0-6,0 pm high, often raised at the

nodes into slender, blunt projections. Chromosome

number n = 8 (Figure II) (Bornefeld 1984, for R.

limbatoides, nom. prov.). (Also reported as 8 by

Berrie (1975), for R. nigrosquamata).

The plants grow on sandy red soil, on black turf,

on dolomitic or on disturbed, calcareous soil, the lat-

ter also noted by Jones (1957) and by Volk (1984, for

R. limbatoides, nom, prov.). They have also been

collected near waterfalls and seepages (S. M. Perold

394), and often show a preference for lightly shaded

places beneath Acacia, Kirkia or Adansonia trees.

R. congoana has been recorded from Nigeria:

Jones 1154 (Herb Jones!), Jones 1168 (Herb.

Jones!); Tanzania: Jones 699 (Herb. Jones!), Jones

2252 (Herb. Jones!) (as R. nigrosquamata) and from

Uganda: Gittins 12122 (Herb. Jones!).

Besides his type specimen from Victoria Falls,

Zimbabwe, Arnell (1963)** reported R. rhodesiae

from the Gold Coast, Nigeria, Uganda, Tanganyika

(= Tanzania), as well as from Egypt (as R. aegyp-

tiaca), but he gave no details of the localities, except

for the specimen from Egypt.

Berrie’s collections (1975) of R. nigrosquamata

are from Sierra Leone (near Freetown); Pettet

(1967) reports plants very similar to R. nigrosqua-

mata from Sudan: Khartoum Province; Jones (1957)

mentions the closely similar R. kassaica, a manu-

script name used by Stephani, from the Belgian

Congo [Zaire].

In southern Africa R. congoana is known from

South West Africa/Namibia and from the northern,

eastern and southern parts of Transvaal. Figure 4.

DISCUSSION

The types of the synonyms cited were examined

and compared.

1. R. congoana Steph. and R. nigrosquamata E. W.

Jones

* O. H. Volk (pers. comm.) drew my attention to a fine, deli-

cate reticulation faintly visible beneath the exine.

** E. W. Jones (pers. comm.) informs me that Arnell was citing

his (Jones’s) records of R. ' rhodesiae ’ sensu Jones, so that the dis-

tribution given by Arnell is in part that of R. atropurpurea.

Jones (1957) distinguished the above two species

on the following differences observed by him:

(a) behaviour of the thallus margins when drying :

in R. congoana, they become inflexed and ‘inrolled’,

and even remain inflexed near the apex on re-wet-

ting; in R. nigrosquamata, the opposite margins

meet 'face to face’ along the middle of the thallus;

(b) the thickness of the thalli: Jones states that R.

congoana is quite distinct from R. nigrosquamata in

its ‘thinner thallus’.

On the other hand, Jones found some resem-

blance in the scales of the two species; in both he

described them as large, imbricate and violet-black.

His descriptions and illustrations of the spores of the

two species are also similar (see also SEM micro-

graphs, Figures 5A-D, 6A-D).

The behaviour of the thallus margins when drying,

is not regarded as conclusive, since in R. nigrosqua-

mata (for example Jones 2252) even on the same

branch, one lobe had the margins and scales tightly

inflexed and meeting along the middle, whereas in

another lobe, the sides and apex were only raised

and partly folded inwards. Berrie (1975) reported

that thalli of the hygromorphic form of R. nigrosqua-

mata, were closely applied to the moist soil. On dry-

ing, the upper surface became strongly concave, but

the margins did not completely leave the ground. In

the xeromorphic form, the margins folded inwards

on drying and the plants ‘buried’ themselves.

With regard to the thickness of the thalli, trans-

verse sections found with the holotype of R. con-

goana (M. de F. Voz s.n. in G 13336) are 0,55-0,65

mm thick. Stephani’s drawings and these sections

are scarcely ‘thinner’ than usual. They also show a

distinct groove, which he describes as well (1898),

but my examination of the thalli, reveal them to be

thin, flat and expanded, with the groove only pres-

ent at the apex. Gittins 12122 (Herb. Jones!), col-

lected at Murchison Falls, presumably a fairly damp

habitat (although without the hyaline scale margins

Berrie (1975) reported for the hygromorphic form of

R. nigrosquamata), are 0,4 (-0,5) mm thick, some-

what thinner (but not broader) than R. nigrosqua-

mata thalli, which Jones stated to be 0, 6-0,8 (-0,9)

mm thick. Abeywickrama (1945) observed: ‘In-

crease in moisture, accompanied by shading, re-

sulted in the thallus becoming broader and thinner

. . which may account for the relative thinness of

the Gittins specimens.

In the light of the above, it is concluded that R.

congoana and R. nigrosquamata are not two differ-

ent species, but that R. nigrosquamata should be

treated as a synonym of R. congoana.

2. R. nigrosquamata E. W. Jones and R. berriei E.

W. Jones

Jones (1957) distinguished these two species be-

cause of the following differences:

(a) R. nigrosquamata with the scales large, imbri-

cate and completely violet-black;

(b) R. berriei with the scales small, distant, en-

tirely hyaline or violet with hyaline margins.

196

Bothalia 16,2 (1986)

FIGURE 2. — Riccia congoana ( Smook 5139, PRE). Thallus, scales and epithelium. A, dorsal surface view of

thallus with young ostioles along groove; B, apex of thallus with groove and scales; C, position of scales

along margin; D, dorsal epithelial cells (SEM micrographs by S. M. Perold). Scale bars on A = 500 pm; on

B-D = 100 pm.

He remarked, however, that the spores of the two

species bear a close resemblance.

Berrie (1975) studied the same colonies of plants

during wet and dry seasons and concluded that they

represented two forms of the same species, a hygro-

morphic form with small hyaline scales and a xero-

morphic form, with large violet-black scales. Berrie

therefore placed R. berriei into synonymy under R.

nigrosquamata.

Jones reported the dimensions of the thalli grow-

ing in wet conditions to be 0,6-0, 8 mm thick and

2, 5-3, 5 mm wide. They are slightly thinner and

wider than those he gave for the xeromorphic form,

0,7-0, 9 mm thick and 2, 0-2, 5 mm wide (see Abey-

wickrama’s observation above).

3. R. rhodesiae S. Arnell and R. aegyptiaca S. Ar-

nell

It is probable that Arnell did not see Stephani’s R.

congoana. He described R. rhodesiae (1952) and R.

aegyptiaca (1963b), two geographically widely separ-

ated plants. He drew no comparisons between them,

although he referred to similarities and differences

between R. aegyptiaca and other species. His mem-

ory may have failed him, or else his own inaccura-

cies, listed below, misled him (as they did others):

(a) in his key (1963a), he placed R. rhodesiae

under ‘smaller plants . . .’ together with R. capensis

sensu Arnell, which is truly small, its lobes being less

than 1 mm wide and under 5 mm long. R. rhodesiae

is by no means small; as Arnell states the lobes are

5-8 mm long and they are much wider than 1mm

(See under ‘b\ below);

(b) in the Latin diagnosis, the width of the lobes

is given as 3-4 mm, but it was left out in the English

description (1952) and also in Hepaticae of South

Africa (1963a);

(c) the dark purple scales were described as ‘tri-

angular-lanceolate’, which is incorrect, as they are

crescent-shaped or rounded;

(d) the type specimens of R. rhodesiae are a

mixed collection and most of the material is R. atro-

purpurea Sim (See below).

Although Arnell’s description is inexact, his draw-

ing of the spore (Figure 7B), and a slide of spores

prepared by him (on loan from S) (Figure 7A),

clearly indicate that he was referring to the R. rhode-

siae portion of the collection. Spores collected from

the type specimen by me are similar, but the tall thin

areolar borders are less conspicuous (Figure 7C &

D).

The thalli and scales of R. rhodesiae and R. aegyp-

tiaca show a close resemblance. The spores of the

type of R. aegyptiaca, M. Kassas s.n. (S!), appear to

have lower and slightly thicker areolar borders, with

Bothalia 16,2 (1986)

197

FIGURE 3. — Riccia congoana ( S . M. Perold 394, PRE). Spores. A & B, spore faces with areolae; C, margin with

tall areolar borders and nodes with projections; D, thin, fragile borders. ( A-C, SEIVT micrographs; D, LM

(light microscope) by S. M. Perold). Scale bars on A-C = 50 pm; diameter of spore on D ± 130 pm.

fewer papillae at the nodes (Figure 7E & F). Their

light yellow colour and the many malformed ones,

suggest somewhat ‘younger’ spores, but not those of

a different species.

R. rhodesiae and R. aegyptiaca are therefore con-

sidered to be conspecific and both are regarded as

synonyms of R. congoana on account of their

grooved wide thalli, sloping flanks, distinctive dark

coloured scales and spores with angular, generally

thin-walled areolae.

4. R. rhodesiae sensu E. W. Jones non S. Arnell and

R. atropurpurea Sim

Because of Arnell’s inaccuracies and the mixed

collections, Jones (1957) mistakenly identified the

R. atropurpurea portion of the specimens as R. rho-

desiae.

In his description of R. rhodesiae , Jones comments

that ‘Arnell did not note the hyaline margins to the

thallus and scales . . The thalli of R. atropurpurea

have hyaline margins and so do the scales.

In R. rhodesiae S. Arnell the thalli never have

hyaline margins, although the scales may have them

in the hygromorphic form, as Berrie reported (1975)

(not seen by me, however).

Jones’s illustrations and description of the spores

clearly refer to the spores of R. atropurpurea, which

are blackish brown and have low, thick-walled areo-

lae (Figure 8B); Arnell’s drawing of the spores of R.

rhodesiae shows the areolae to be thin-walled, with

larger, angular areolae (Figure 7B). Comparison of

the R. atropurpurea portion of Arnell 1291 and its

spores (Figure 8 A & C), with the types of R. atro-

purpurea, Sim 8112 (CH1023) (PRE!) and Sim s.n.

(CH1024) (PRE!) (Figure 8D), confirms beyond

doubt that they belong to the same species.

The following specimens from Herb. Jones are

therefore now identified as R. atropurpurea Sim:

FIGURE 4. — Distribution map of R. congoana in southern

Africa.

198

Bothalia 16,2 (1986)

FIGURE 5. — Riccia congoana [Type M. de F. Voz s.n sub G13336 (G-Herb. Steph)]. Spores. A, B, C, D, spore

faces with areolae. (A-C, SEM micrographs; D, LM (light microscope) by S. M. Perold). Scale bars on

A-C = 50 pm; diameter of spore on D ± 100 pm.

FIGURE 6. — Riccia nigrosquamata ( Jones 699, isotype. Herb. Jones). Spores. A, B, C, D, spore faces with

areolae. (A-C, SEM micrographs; D, LM (light microscope) by S. M. Perold). Scale bars on A-C = 50 pm;

diameter of spore on D ± 110 pm).

Bothalia 16,2 (1986)

199

FIGURE 7. — Riccia rhodesiae and R. aegyptiaca. Spores. A, LM (light microscope) micrograph of spore on

Arnell’s slide 1291, portion of type specimen of R. rhodesiae in S; B, enlarged copy of Arnell’s drawing of

the spore ornamentation (1952); C, D, LM and SEM micrographs resp., of spores collected from Arnell

1291 (portion of type specimen on loan from S); E, LM micrograph of spore collected from M. Kassas s.n.

(type secimen of R. aegyptiaca, on loan from S); F, enlarged copy of Arnell’s drawing of spore ornamenta-

tion (Arnell 1963b) areolar borders too thick, due to enlargement of drawing. Diameter of spores on A, C

& D ± 110 pm; on E ± 90 pm. All SEM and LM micrographs by S. M. Perold.

Jones 685 (Tanzania); Wood 1190 (mixed with R.

okahandjana S. Arnell (Uganda); Jones 457 (Nige-

ria) and Boughey s.n., Oct. 1953 (mixed with R. con-

goana Steph.) (Ghana).

5. R. discolor L. & L., R intermedia E. W. Jones

and R. billardieri Mont. & Nees

Vanden Berghen (1972) in his description of R.

intermedia E. W. Jones (placed in synonymy under

R. discolor L. & L. by Pande & Udar (1957)) adds in

a note rhodesiae S. Arnell (1952) Bot. Not., p.

313. est peut-etre identique a Fespece decrite par E.

W. Jones’, which expresses some uncertainty on his

part. Judging by the specimens of R. intermedia ( =

R. discolor ) in Herb. Jones that were examined, I

tend to disagree with him, because the lobes are

much elongated, have parallel sides, develop a

strong purple colour dorsally and the assimilation

tissue appears less compact. It is reported to be

strictly dioecious, and the spores have ridges equally

high and not raised at the nodes, with 8-10 areolae

200

Bothalia 16,2 (1986)

FIGURE 8. — Riccia atropurpurea Sim. Spores. A, LM (light microscope) micrograph of spore of R. atropurpurea

portion of Arnell 1291 (portion of type secimen of R. rhodesiae)-, B, enlarged copy of Jones’s drawing of the

spore ornamentation of R. rhodesiae sensu Jones; C, SEM micrograph of areolae and borders of R. atropur-

purea portion of Arnell 1291\ D, LM (light microscope) micrograph of spore of syntype of R. atropurpurea,

Sim CH 1024. Diameter of spores on A & D = 100 pm; scale bars on C = 50 pm. All SEM and LM

micrographs by S. M. Perold.

across the diameter of the spore, 7,5-10,0 pm wide.

Vanden Berghen makes no mention of R. rhodesiae

as described by Jones.

R. billardieri Mont. & Nees as described and illus-

trated by Pande & Udar (1957), seems to be closer

to R. congoana, and indeed, the single specimen of

R. billardieri (leg. et det. V. Schiffner, IV 1894, fide

E. Levier) from Java (Indonesia) that was exam-

ined, reveals a marked similarity to R. congoana,

both in vegetative as well as in spore characters.

However, in view of the problems experienced by

some of the earlier Indian authors in distinguishing

R. discolor and R. billardieri (as well as their several

synonyms) from one another (Udar 1957; Pande &

Udar 1957), intensive study of more material of

these two species is imperative, before any decision

about their relationship to R. congoana can be

reached.

CONCLUSION

There has obviously been much confusion about

the R. congoana species-complex and it is hoped that

this study will stimulate renewed interest in it.

The distribution of R. congoana covers a large

area, where widely differing climatic conditions un-

doubtedly significantly affect the morphology of the

plants.

I have been able to examine a large number of

specimens from different habitats and have also cul-

tivated plants for a considerable period of time; I

find no significant characters that differ so consist-

ently that the continued separation of the species

seems justified. It is therefore proposed that R. rho-

desiae, R. nigrosquamata and R. aegyptiaca be re-

garded as synonymy of R. congoana.

ACKNOWLEDGEMENTS

I particularly want to thank Prof, (emer.) Dr

O. H. Volk of Wurzburg University for making

available to me a number of his specimens, his notes

and sketches, and for his valuable advice and con-

structive criticism of an earlier draft of this paper. I

am also sincerely grateful to Dr E. W. Jones, Ox-

ford, for the loan of his specimens and for his helpful

suggestions after reading the manuscript. Many

thanks to Dr. habil. T. Bornefeld, Am Reele 1,

D-8706 Hochberg, Wurzburg, Germany, for the

chromosome counts and figures of R. limbatoides

Volk ined. Sincere thanks are due to the Curators of

BOL, S and G for the loan of the type specimens. I

Bothalia 16,2 (1986)

201

owe a large debt of gratitude to Miss L. Smook and

Dr. H. F. Glen for their help in collecting speci-

mens; to Mrs A. J. Romanowski for the many micro-

graphs she developed and printed, to the artist, Ms

G. Condy and to Mrs M. van der Merwe for typing

the manuscript.

REFERENCES

ABEYWICKRAMA, B. A. 1945. The structure and life history

of Riccia crispatula Mitt. Ceylon Journal of Science A12:

145-153.

ARNELL, S. 1952. Hepaticae collected in South and west Africa

1951. Botaniska notiser 105: 307-315.

ARNELL, S. 1957. Hepaticae collected in South West Africa by

Prof. Dr O. H. Volk. Mitteilungen aus der Botanischen

Staatssammlung, Miinchen 16: 262-272.

ARNELL, S. 1963a. Hepaticae of South Africa. Swedish National

Scientific Research Council, Stockholm.

ARNELL, S. 1963b. Some hepatics new to Egypt. Botaniska no-

tiser 116: 7-10.

BERRIE, G. K. 1975. The biology of a west African species of

Riccia L. Journal of Bryology 8: 443-454.

BORNEFELD, T. 1984. Chromosomenanalyse der Gattung Ric-

cia von Slid- und SW-Afrika und allgemeine Bemerkungen

zur Zytogenetik der Lebermoose. Nova Hedwigia 40:

313-328.

JONES, E. W. 1957. African hepatics XIII. The Ricciaceae in

tropical Africa. Transactions of the British Bryological So-

ciety 3: 208-227.

PANDfi, S. K. & UDAR, R. 1957. Genus Riccia in India. 1. A

reinvestigation of the taxonomic status of the Indian

species of Riccia. Journal of the Indian Botanical Society

36: 564-579.

PETTET, A. 1967. Bryophytes of the Sudan 1. Khartoum Pro-

vince. Transactions of the British Bryological Society I Jour-

nal of Bryology 5: 316-322.

SIM, T. R. 1926. The bryophytes of South Africa. Transactions of

the Royal Society of South Africa 15.

STEPHANI, F. 1898. Species hepaticarum. Bulletin de I'Herbier

Boissier 6: 309^111.

UDAR, R. 1957. On the synonymy of some Indian species of Ric-

cia. Current Science 26: 20-22.

VANDEN BERGHEN, C. 1972. Hepatiques et Anthocerotees.

Resultats scientifiques de i exploration hydrobiologique du

Bassin Lac Bangweole & Luapula 8: 1-202.

VOLK, O. H. 1984. Pflanzenvergesellschaftungen mit Riccia- Ar-

ten in Sudwestafrika (Namibia). Vegetatio 55: 57-64.

SPECIMENS OF RICCIA CONGOANA EXAMINED

Glen 1378, 1401, 1402, 1423, 1428 PRE.

Hardy 6446 PRE. Hoffman CH 4513 PRE.

5. M. Perold 130, 173, 175, 394, 732, 738, 744, 746, 747, 757, 762,

771, 763, 778, 779, 797 PRE.

/. M. Relief 248, 249 PRE.

Smook 5118b, 5139 PRE.

Vogel T82A M, PRE. Volk00722, 00747, 00978, 841693a M, PRE.

Bothalia 16,2: 203-226 (1986)

Numerical taxonomic studies in the subtribe Ruschiinae (Mesem-

bryanthemaceae) — Astridia, Acrodon and Ebracteola

H. F. GLEN*

Keywords: Acrodon, Astridia, Ebracteola, Mesembryanthemaceae, numerical taxonomy, Ruschiinae, southern Africa

ABSTRACT

A numerical taxonomic study of three genera of the Ruschiinae (Mesembryanthemaceae) is presented. Seven

species are recognized in Astridia. Four species are recognized in Acrodon and two new combinations are made:

A. leptophyllus (L. Bol.) Glen and A. duplessiae (L. Bol.) Glen. Five species are recognized in Ebracteola and two

new combinations are made: E. wilmaniae (L. Bol.) Glen and E. fulleri (L. Bol.) Glen. This study is largely based

on the cited herbarium material, and the characters used are mainly the following: dimensions of plants, leaves and

internodes, number and dimensions of parts of flower and fruit, colour of petals, and colour, dimensions and

surface structure of seeds.

UITTREKSEL

’n Numeriese taksonomiese ondersoek van drie genera van die Ruschiinae (Mesembryanthemaceae) word aan-

gebied. Sewe spesies word in Astridia erken. Vier spesies word in Acrodon erken en twee nuwe kombinasies word

gemaak : A. leptophyllus (L. Bol.) Glen en A. duplessiae (L. Bol.) Glen. Vyf spesies word in Ebracteola erken en

twee nuwe kombinasies word gemaak : E. wilmaniae (L. Bol.) Glen en E. fulleri (L. Bol.) Glen. Hierdie onder-

soek is in ’n groot mate gegrond op die gesiteerde herbariummateriaal en die kenmerke wat gebruik is, is hoof-

saaklik die volgende: afmetings van plante, blare en litte, aantal en afmetings van blom- en vrugdele, kleur van

kroonblare, en kleur, afmetings en oppervlakstruktuur van sade.

INTRODUCTION

The subtribe Ruschiinae is one of the largest

groups in the family Mesembryanthemaceae, with

some 540 described species and infraspecific taxa in

17 described genera. Most of these genera have not

been revised since they were first described, except

for partial revisions of the genera occurring in

SWA/Namibia (Friedrich 1970). The only exception

is the genus Astridia, of which a brief account was

published by Bolus (1961b, key revised in Bolus

1966a).

The subtribe is defined by the fruits, which are 5-

locular, with covering membranes and placental tu-

bercles, and (usually) without valve wings. In habit,

members of this subtribe range from dwarf succu-

lents which are not as reduced as, for example, Li-

thops or Conophytum, to some of the largest shrubs

in the family Mesembryanthemaceae. The leaves are

always opposite, and are usually triquetrous to semi-

terete. Flowers are solitary or in larger or smaller

cymose inflorescences, and individual flowers vary

from among the smallest to among the largest in the

family. Petal colours found in this subtribe include

the full range of yellows, reds, pinks, magentas and

whites found in the family; in some species each pe-

tal has a central dark-coloured longitudinal stripe,

but petals in which the base and apex are of different

colours are very rare.

Taxonomic work on this group was started with

the intention of producing a comprehensive account

for the Flora of southern Africa. Rising costs and in-

creasingly stringent limits on what was financially vi-

* Botanical Research Institute, Department of Agriculture and

Water Supply, Private Bag X101, Pretoria 0001, RSA.

able rendered this goal unattainable in the foresee-

able future, and so it was determined to complete

treatments of the minor genera where this could be

done with minimum extra input. In the case of both

Ebracteola and Acrodon, about half of the species

have, until this treatment, been included in the

genus Ruschia. This illustrates one of the major diffi-

culties in the taxonomic treatment of this subtribe,

namely the generally poor delimitation of genera.

The apparently ambiguous limits of genera in the

Ruschiinae is, no doubt, due to the fact that newly-

discovered species have been described in great

numbers over a long period of time, and assigned to

genera which have not been revised since they were

first described. In particular, it appears that a re-

vision of the over 300 species at present assigned to

the genus Ruschia would, if it were to be of benefit

to the users of taxonomic treatments, distribute

these species among about three major genera and

some (extant) minor ones. This process is started in

this paper.

METHODS AND MATERIALS

Both dried and living specimens, the latter mainly

cultivated, were examined in the course of this

study. For numerical processing, both scored and

measured characters were recorded, and an Opera-

tional Taxonomic Unit (OTU) was defined as being

equivalent to one micro-taxon as recognized by L.

Bolus. As her stated aim (Bolus 1936-1958: iii) was

to describe as much as possible of the variation in the

family as new taxa, so that the types would remain in

South Africa ‘for the convenience of future work-

ers’, it was found that the danger of overlooking any

variation in the specimens examined by her was neg-

ligible. Very few, if any, specimens not referable to

any of her micro-taxa have been collected since her

204

Bothalia 16,2 (1986)

death. Scored characters were taken as being for all

obtainable specimens that could be regarded as be-

longing to the OTU in question. Measured charac-

ters were taken from as many individuals as possible

with a maximum of 25, subject to the same con-

straint.

Eighty-six characters were recorded; some of

these were noted as minimum, mean and maximum

and others as minimum and maximum without a

mean, yielding a total of 121 character strings (Hall

1973), as listed in Table 1. A preliminary examina-

tion of a very incomplete portion of this matrix was

made using the BOLAID package of programs for

numerical taxonomy (Hall 1973); this was the basis

for the taxonomic observations of Glen (1984). It

was found to be financially unviable to continue pro-

cessing data for the whole of the subtribe Ruschiinae

(538 OTU’s) using BOLAID, so a cheaper and

faster system was sought and found in NT-SYS

(Rohlf et al. 1977). BOLAID was used on the Bur-

roughs B7700 of the Department of Agriculture and

Water Supply, while NT-SYS was made available by

the CSIR on their CDC computer. The present ac-

count is derived from an examination of 103 OTU’s

drawn from all genera recognized as belonging to the

subtribe Ruschiinae.

TABLE 1. — List of 86 characters used. Character strings (Str. ) :

3 = minimum, mean and maximum; 2 = minimum and

maximum; 1 = mean or invariant except where other-

wise stated

No. Str. Description

1 3 Leaf length (greater leaf of a pair)

2 3 Leaf breadth (greater leaf of a pair)

3 3 Leaf thickness (greater leaf of a pair)

4 3 Leaf length (lesser leaf of a pair)

5 3 Leaf breadth (lesser leaf of a pair)

6 3 Leaf depth (lesser leaf of a pair)

7 1 Plant height

8 1 Plant diam.

9 2 Flower colour (betacyanin)

10 2 Flower colour (betaxanthin)

11 1 no. of bracts

12 1 no. of sepals

13 2 no. of petals

14 2 no. of stamens

15 2 no. of staminodes

16 1 no. of stigmas

17 1 max. length of bracts

18 1 max. width of bracts

19 1 max. length of outer sepals

20 1 max. width of outer sepals

21 1 max. length of inner sepals

22 1 max. width of inner sepals

23 3 length of petals

24 1 max. width of petals

25 3 length of stamens

26 3 length of staminodes

27 3 length of stigmas

28 1 length of pedicel

29 1 diam. of pedicel

30 1 diam. of flower

31 1 diam. of capsule

32 1 length of capsule

33 1 ± no. of flowers per inflorescence

34 1 width of central discolor, stripe in petals (0 if no stripe)

35 2 stripe colour (betacyanin)

36 2 stripe colour (betaxanthin)

37 1 no. of locules per capsule

38 1 extent of covering membrane

The first step in processing the data with NT-SYS

was to standardize the raw matrix so that each

character had a mean of zero and a standard devia-

tion of one. The standardized data matrix was then

used for further processing, thus ensuring that all

characters would be strictly equally weighted in later

computations. A matrix of correlations was calcu-

lated according to an algorithm described by Rohlf et

al. in the NT-SYS manual. An ‘average taxonomic

distance’ matrix, giving a measure of the dissimilar-

ity between pairs of OTU’s, was calculated accord-

ing to the algorithm of Sokal (1961). This gives, in

effect, a normalized matrix of Euclidean distances

between pairs of OTU’s. Finally, NT-SYS calcu-

lated cophenetic matrices and dendrograms for both

distance and correlation matrices using UPGMA

(unweighted pair-group method with arithmetic av-

erages; Sneath & Sokal 1973). The dendrograms are

referred to below as distance and correlation pheno-

grams, respectively.

The classification and circumscriptions of taxa

presented here were derived from both distance and

correlation phenograms, with constant reference

back to the original specimens.

Bothalia 16,2 (1986)

205

In the specimen citations below, the following ab-

breviations, which are not found in Index Herbario-

rum (Holmgren et al. 1981), indicate garden acces-

sion numbers:-

KG - Karoo Garden, Worcester

NBG - National Botanical Garden, Kirstenbosch.

Used where the number is of the form <accession

number>/<date>. e.g. 1234/56 is no. 1234 of 1956

SUG — Stellenbosch University Garden

All other abbreviations in the specimen citations in-

dicate herbaria and are according to Index Herbario-

rum.

1. ASTRIDIA

The genus is a very natural and cohesive group of

species, not only very similar in appearance but also

confined to a small area in the lower reaches of the

Orange River.

In habit, Astridia Dinter is very similar to Rusch-

ianthemum and Stoeberia, all three of which occur in

the same area. Ruschianthemum and Stoeberia differ

markedly from Astridia in having small (± 10 mm in

diameter) white flowers rather than large showy

ones, in having capsules showing varying degrees of

schizocarpy rather than the hygrochastic capsules of

Astridia , and non-baculate seeds with well differen-

tiated embryo and micropylar regions (see Figure 1).

Astridia can be separated from species of Ruschia of

similar habit by its flower size, bracts, stamens, seed

surfaces, and by the leaf surface, which is glabrous in

Ruschia but velutinous in Astridia. In addition, the

flowers of Astridia are solitary, whereas those of

Ruschia are typically borne in large, repeatedly

branched cymes. The overall appearance of plants of

the genus Astridia is so distinctive that they are un-

likely to be confused with any other group of Me-

sembryanthemaceae.

Dinter (1926) published the new combination As-

tridia velutina Dinter for the plant which he had

named Mesembryanthemum velutinum Dinter (non

L. Bob), but he gave only a very brief description of

his new genus. Schwantes (1927) supplied an

amended generic description in the following year,

and recognized a second species, A. maxima (Haw.)

Schwant., based on M. maximum Haw. The distin-

guishing characters of the new genus were stated to

be the seeds, which appeared to be covered with hol-

low spines, and the overall form of the plants.

N. E. Brown (1928) noted that although no distin-

guishing characters could readily be found for the

genus, plants were so distinctive in overall appear-

ance that the genus was possibly a good one. He also

noted that the seed character mentioned by

FIGURE 1. — SEM photographs of seeds of A, Astridia velutina; B, Ruschia maxima; C, Stoeberia beetzii; D. Braunsia geminata.

Scale bar= 100pm.

206

Bothalia 16,2 (1986)

Schwantes was not unique in Mesembryanthema-

ceae. Bolus (1961b) noted a number of relatively

subtle characters by which Astridia can be distin-

guished from Ruschia and other genera. These in-

clude:

1, the manner of attachment of the leaves to the

stem (in Ruschia old leaves may be broken off com-

plete, but in Astridia a portion of leaf base always

adheres to the stem);

2, the form of the bracts (cymbiform in Astridia

but semi terete to triquetrous in Ruschia );

3, the ciliate inner stamens of Astridia, as opposed

to the glabrous stamens of Ruschia.

Bolus admitted the possibility that any or all of

these characters may be found in the genus Ruschia,

but the combination of all three, together with the

growth habit, appears to define a natural group.

Friedrich (1970) distinguished between Astridia

and species of Ruschia of similar habit by

1, the large flowers of Astridia (±50 mm in di-

ameter when open in Astridia; ± 20 mm in Ruschia );

2, the form of the bracts (cymbiform in Astridia;

semiterete to triquetrous in Ruschia);

3, the stigmas, which are always six in Astridia and

usually five in Ruschia (this difference is not as sig-

nificant as it may seem at first sight: carpel numbers

are variable throughout the Mesembryanthemaceae,

and this variability increases in proportion to the

usual number of carpels).

Friedrich was the first to suggest that too many

taxa had been described in the genus, and he recog-

nized six species and no infraspecific taxa in SWA/

Namibia.

The seed character, used by Schwantes in the orig-

inal delimitation of the genus, is best seen in the type

species, A. velutina, where long, spine-like baculae

cover the entire surface of the seed (Figure 1A).

These characteristic baculae are not generally as well

developed in the other species of the genus, and may

be restricted to the micropylar region of the seed,

the surface of the cells of the embryo region of such

seeds being in the form of low, roughly conical bacu-

lae (Figure 4A-D). As Brown (1928) has pointed

out, this character is not unique to Astridia, being

present, and in fact better developed, in Braunsia

(see Figure 1), Antegibbaeum and possibly other

genera.

On the south bank of the Orange River, the genus

is found in the Richtersveld, in Acocks’s (1975)

Western Mountain Karoo, Succulent Karoo and Na-

maqualand Broken Veld, in an area no more than

100 km x 100 km; on the north bank, it is restricted

to a hardly larger area of Giess’s (1971) ‘Desert and

succulent steppe (winter rainfall area)’.

The phenograms used to generate the classifica-

tions are shown in Figures 2 & 3. The overall corre-

lation coefficient of the distance phenogram was

slightly less than that of the correlation phenogram

(0,75 as against 0,80). Nevertheless, it was found by

checking back against the original specimens that the

former yielded groups that were less likely to lead to

the misidentification of new specimens than the lat-

ter. In cases where the two phenograms differ, the

distance rather than the correlation dendrogram was

followed in the construction of groups and recogni-

tion of taxa.

Astridia Dinter in Gardeners’ Chronicle, series 3,

80: 430 (1926); Dinter & Schwant. in Schwant.: 16

(1927); N. E. Br.: 266 (1928); L. Bol.: 173 (1961b);

{Z

. alba

vanbredai

■ rubra

- syvarlporlen-

sis

- dulcis

longifolia

- latisepala

herrei

- citrina

- speciosa

- hallii

- ruschii

blanda var.

blanda

blanda var.

lalipelala

velutina var.

' lutata

blanda var.

anguslata

hillii

velutina var.

velutina

- vanheerdei

FIGURE 2. — Phenogram of Astridia calculated from a distance matrix using UPGMA. Irrelevant OTU’s are omitted.

Bothalia 16,2 (1986)

207

alba

valutina

velutina var.

lutata

blanda var.

angustata

dulcia

latisepala

long i folia

vanbradai

rubra

swartportan-

sls

herrei

hellii

ruschii

blanda var.

blanda

blanda var.

latipetale

speciosa

citrine

hillii

vanheerdei

0.2 0.3 0.4 05 06 0.7 00

FIGURE 3. — Phenogram of Astridia calculated from a correlation matrix using UPGMA. Irrelevant OTU’s are omitted.

Friedrich: 17 (1970); Herre: 88 (1971); Dyer: 99

(1975). Type species: Astridia velutina Dinter &

Schwant.

Robust, erect, woody shrubs. Leaves opposite,

succulent, not toothed, velutinous, obscurely trique-

trous, usually grey, blue-grey or glaucous green,

usually firmly attached and not falling readily. Flow-

ers solitary, on relatively short pedicels or subsessile,

the pedicels each with a pair of relatively small, dis-

tinctively boat-shaped bracts which tend to remain

attached to the plant on drying. Sepals 6, in two se-

ries, the outer 2 fleshy, the inner 4 less so, and with

membranous margins. Petals 40 or more, in 1 to

many series, lorate, narrowly oblanceolate or nar-

rowly obovate, apices obtuse, white to pale yellow,

orange-red or scarlet. Staminodes present or absent.

Stamens numerous, inner filaments densely ciliate.

Stigmas 6, subulate to filiform. Capsules 6-locular;

covering membranes well developed; valve wings

absent or awn-like; placental tubercles present; ex-

panding keels diverging, unadorned. Seeds various

shades of maroon to black, with long, spine-like ba-

culae at least on the micropylar region.

KEY TO THE SPECIES OF ASTRIDIA

la Leaves 2-3 times as long as broad:

2a Pedicels 5-6 mm long 1. A. velutina

2b Pedicels over 10 mm long, usually 13-14 mm long:

3a Staminodes absent; fruit diameter about 1,5 times fruit depth, fruit about 14 mm in diameter; petals

pink to white 6. A. hallii

3b Staminodes present; fruit diameter roughly equal to fruit depth, fruit about 11 mm in diameter;

petals yellow to white 4. A. citrina

lb Leaves (3,5-) 4-10 times as long as broad:

4a Stigmas longer than the stamens, about 9 mm long; flowers about 70 mm in diameter

5. A. speciosa

4b Stigmas roughly as long as the stamens, about 7 mm long; flowers about 50 mm in diameter:

5a Internodes about 15 mm long 3. A. herrei

5b Internodes about 25 mm long:

6a Staminodes absent: flowers and fruit subsessile 7. A. vanheerdei

6b Staminodes present; flowers and fruit distinctly pedicellate 2. A. longifolia

1.1 Astridia velutina Dinter & Schwant. in

Zeitschrift fur Sukkulentenkunde 3: 16 (1927). A.

dinteri L. Bol.: 170 (1961b), nom. nov. pro A. velu-

tina.

Mesembryanthemum velutinum Dinter: 149 (1923), non L. Bol.

(1922). Type: SWA/Namibia, Klinghardtgebirge, 15 September

1922, Dinter 3792 (B, holo.!; Z, iso.!).

A. velutina Dinter & Schwant. var. lutata L. Bol.: 95

(1928-1935; published 1929). A. dinteri L. Bol. var. lutata L. Bol.

ex Jacobsen: 413 (1974), nom. nov. pro A. velutina var. lutata.

Type: Cape, between Arris and Sendelingsdrift, October 1926,

Pillans 5725 (BOL!).

A. blanda L. Bol.: 123 (1961c); Jacobsen; 413 (1974). Type:

SWA/Namibia, without exact locality, cultivated in Windhoek

Government Garden, January 1937. Holloway 1 (BOL!).

A. blanda L. Bol. forma angustata L. Bol.: 171 (1961b); Jacob-

sen: 413 (1974). Type: SWA/Namibia, without precise locality,

cultivated in Windhoek Government Garden, January 1937,

Rusch & Erni sub Holloway 33.

A. blanda L. Bol. forma latipetala L. Bol.: 171 (1961b); Jacob-

sen: 413 (1974). Type: SWA/Namibia without precise locality,

cultivated in Windhoek Government Garden, January 1937,

Rusch & Erni sub Holloway 17 (BOL!).

208

Bothalia 16,2 (1986)

FIGURE 4. — SEM photographs of seeds of A, Astridia longifolia; B, A hallii; C, A, herrei; D, A. citrina. Scale bar= 100pm.

A. hillii L. Bol.: 301 (1962b); L. Bol.: 172 (1965); Jacobsen: 413

(1974). Type: Cape, Grootderm. August 1956, L. J. Hill s.n. in

BOL 27253 (BOL!).

Robust shrubs 200-300 mm tall. Stems pale buff to

dark brown when young; internodes ± 15 x 4 mm.

Leaves minutely velutinous, 15-34 mm long, obscu-

rely keeled, 7-14 mm wide and slightly less thick.

Pedicel ±7 x 2,5 mm. Bracts up to 12 mm long and

6 mm thick. Flowers ± 30 mm in diameter when

open. Sepals 6, outer pair up to 7 x 6 mm, inner 4 up

to 7 x 5 mm. Petals 40-70 in 1-2 series, white to

pink, 12-23 x up to 3 mm, but often narrower. Sta-

minodes present, 2-10 mm long, distinct from petals.

Stamens many; filaments 6-9 (-11) mm long. Stig-

mas subulate to filiform, shorter than longest sta-

mens, 4-8 mm long. Capsule dark grey, broadly ob-

conical, ± 11,5 mm in diameter when closed and 8,5

mm long; valve wings absent; placental tubercles

large, radial diameter 1,2 mm. Seeds pale yellow to

dark brown, echinate, 1,1-1, 5 (-1,85) x 0,7-1, 3 x

0,5-1, 2 mm, micropylar region 0,3-0,55 mm long;

baculae very prominent; microbaculae long but vari-

able.

Voucher specimens:

SWA/NAMIBIA. — 2715 (Bogenfels): Sargdeckel (-BC/BD)

Dinter 3792 (B, Z).

CAPE. — 2816 (Oranjemund): between Arris and Sendelings-

drift (-BD), Pillans 5725 (BOL, K); Grootderm (-DA), L.J. Hill

s.n. in BOL 27253 (BOL); Wisura 626 (NBG). 2817 (Vioolsdrift):

Dolomite Peaks (-CA), Wisura 1588 (NBG).

The name Mesembryanthemum velutinum Dinter

(1923) is a later homonym of M. velutinum L. Bol.

(1922), and is therefore invalid in Mesembryanthe-

mum. However, there is no earlier homonym of the

combination Astridia velutina Dinter & Schwant.,

with Mesembryanthemum velutinum Dinter non L.

Bol. as basionym, nor is there any earlier name for

this species. According to Art. 72 note 1 of the Rules

of Botanical Nomenclature, this combination must

be accepted. For this reason, the name Astridia din-

teri L. Bol. was superfluous when published and is to

be rejected as illegitimate (Art. 63.1).

It will be seen from the scatter diagram in Figure 5

that the various entities included in this species can-

not be distinguished on the basis of their leaves. The

same is true for all other characters examined, and

so several previously-accepted names, as listed in the

synonymy above, must become synonyms of A. velu-

tina.

The combination of white to pink flowers, short

pedicels (even of the capsules) and relatively short,

wide leaves distinguishes this species from all others

in the genus. Although the flowers fall rapidly, the

fruits stay on their pedicels for up to two years, and

so may be used for diagnostic purposes at any sea-

son. The distribution of this species is shown in Fig-

ure 6.

Bothalia 16,2 (1986)

209

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FIGURE 5. — Leaf measure-

ments of plants included in

Astridia velutina.

FIGURE 6. — Distribution of Astridia velutina, A ; and Acrodon

bellidiflorus, •.

1.2 Astridia longifolia (L. Bol.) L. Bol. in Jour-

nal of South African Botany 27: 170 (1961b); Jacob-

sen: 413 (1974). Type: Cape, between Sendelings-

drift and Doornpoort, October 1926, Pillans 5830

(BOL!).

Mesembryanthemum longifolium L. Bol.: 196 (1928). Ruschia

longifolia (L. Bol.) L. Bol.: 220 (1936-1958; published 1950);

Rowley: 61 (1956), non L. Bol. (1935).

M. rubrum L. Bol.: 275 (1928-1935; published 1931). Lam-

pranthus ruber (L. Bol.) L. Bol.; 169 (1936-1958; published

1939). R. rubra (L. Bol.) L. Bol.: 220 (1936-1958; published

1950). A. rubra (L. Bol.) L. Bol.: 170 (1961b). Type: Cape,

Swartwater, October 1930, H. Herre s.n. in SUG 9202 (BOL!).

A. latisepala L. Bol.: 169 (1961b); Jacobsen: 413 (1974). Type:

Cape, Helskloof, April 1961, H. Hall s.n. in NBG 120/58 (BOL!).

A. rubra (L. Bol.) L. Bol. var. alba L. Bol.: 170 (1961b). A.

alba (L. Bol.) L. Bol.: 229 (1966b); Jacobsen: 413 (1974). Type:

Cape, Swartpoort, March - April 1961, H. Hall 1308a = NBG

107al58 (BOL!).

A. swartpoortensis L. Bol.: 137 (1963a); Jacobsen: 413 (1974).

Type: Cape, Swartpoort, April 1963, H. Hall s.n. in NBG 107158

(BOL!).

A. dulcis L. Bol.: 173 (1963b); Jacobsen: 413 (1974). Type:

SWA/Namibia, 5 miles north of Sendelingsdrift, March 1960, H.

Hall 1869a = NBG 175a/60.

A. vanbredai L. Bol.: 127 (1966a); Jacobsen: 414 (1974). Type:

Cape, Helskloof, June 1962, P.A.B. van Breda 1694160 (BOL!).

Robust shrubs 200-300 mm tall. Stems pale buff to

dark brown when young, internodes ± 26 x 4,5 mm.

Leaves minutely velutinous, 17-55 (-96) mm long,

strongly keeled, ± 4-8 (-15) mm wide, 5-10 (-20)

mm thick, sheathing stem for 3-5,5 mm. Pedicel ± 9

x 4 mm. Bracts up to 21 mm long and 12,5 mm

thick. Flower 45-50 mm in diameter when open. Se-

pals 6, outer pair up to 17 x 9 mm, inner 4 up to 9,5

x 7,5 mm. Petals 50-90 in 1 - several series, white to

scarlet red, 14-31 x up to 4 mm. Staminodes few to

many, 6,5-13 mm long, distinct from petals. Stamens

many; filaments 2,5-12,5 mm long. Stigmas subulate

to filiform, shorter or longer than longest stamens,

2-10 (-15) mm long. Capsule dark grey, broadly ob-

conical, ± 12,5 mm in diameter when closed and 9,5

mm long; valve wings present or absent, if present

then awn-like; placental tubercles large, radial di-

ameter ± 1,1 mm. Seeds deep maroon, echinate,

0,9-1,45 x (0,65-) 0,85-1,05 x 0,7-0,9 (-1,0) mm,

micropylar region 0,3-0,55 mm long; baculae promi-

nent, usually more so on the embryo region; micro-

baculae long to very long, roughly cylindrical. Chro-

mosome number 2n = 18 (De Vos 1947).

Voucher specimens:

SWA/NAMIBIA. — 2716 (Witputs): Spitskop LU 111 farm

(-DC). Giess & Muller 14380 (M). 2816 (Oranjemund):

Kahanstal (-BB), Dinter 8395 (B).

CAPE. — 2816 (Oranjemund): Swartpoort (-BB), H. Hall s.n.

in NBG 107 a! 58 (BOL); between Sendelingsdrift and Doornpoort

(-BB), Pillans 5830 (BOL, K); 6 miles south of Sendelingsdrift

(-BB), Wisura 677 (NBG).

The scatter diagram in Figure 7 shows that the se-

ven formerly accepted taxa included here can not be

distinguished by their leaves; this also applies to

their seeds. The same lack of distinction extends to

other characters examined, and so the previously ac-

cepted names listed in the synonymy above must be

regarded as synonyms of A. longifolia.

This, the commonest species in the genus, may be

distinguished from all others by the long, relatively

narrow leaves, which are distinctly narrowed at the

210

Bothalia 16,2 (1986)

E

£

L

50L

L

40L

L

30L

L

* “ fl. al ba s . str.

0 - R. dulcis s. str.

® ■ fl . 1 at i sop a 1 a

& “ fl . 1 ong 1 f o 1 ia

$ ■ fl. rubra s. str.

+ - fl. suiartpoortensls

0 - fl. vanbrodal

20L

L

10L

L

0 L

# * 8. *8

0 10 20 30

Le af length, mm

40 50 60 70 00 90

FIGURE 7. — Leaf measure-

ments of plants included in

Astridia longifolia.

base, and the relatively long pedicels supporting the

large, usually red but rarely white flowers and char-

coal-grey capsules. The distribution of this species is

shown in Figure 8.

FIGURE 8. — Distribution of Astridia longifolia, ▲; and Acro-

don parvifolius, •.

1.3 Astridia herrei L. Bol. in Journal of South

African Botany 30: 33 (1964); Jacobsen: 413 (1974).

Type: Cape, Annisfontein, October 1961 and Sep-

tember 1963, H. Herre s.n. in SUG 14693 (BOL!).

Robust shrubs ± 400 mm tall and 400 mm in dia-

meter. Stems pale grey, with internodes about 15 x

6-7 mm when young. Leaves grey to pinkish, 31-51

x 6-10,5 mm and as deep as wide, digitiform to sub-

falcate, obscurely keeled, sheathing the stem for

about 8 mm. Pedicel ± 10 x 4 mm. Bracts up to 13

mm long and 6,5 mm thick. Flower ± 50 mm in di-

ameter when open. Sepals 6, outer 2 up to 9,5 x 8

mm, inner 4 up to 8 x 5 mm. Petals many in about 6

series, magenta to scarlet red, 22-26 x up to 3 mm,

innermost petals merging with staminodes. Stami-

nodes (7,5-) 9-13 mm long. Stamens many; fila-

ments 5-12 mm long; anthers and pollen pale yel-

low. Stigmas narrowly subulate, 5-6 mm long. Cap-

sule broadly obconical, ± 12,5 mm in diameter when

closed and 9 mm long; valve wings absent; placental

tubercles large, radial diameter ±1,3 mm; expand-

ing keels slightly diverging, not fimbriate. Seeds

deep maroon, 1,1—1 ,3 x 0,85-1,00 x 0,70-0,90 mm,

micropylar region 0,35-0,45 mm long; baculae

prominent, those on embryo region somewhat more

so than those on micropylar region; microbaculae

very long, rod-shaped and conspicuous. Chromo-

some number 2n=18 (Albers & Haas 1978).

Voucher specimens:

CAPE. —2816 (Oranjemund): Annisfontein (-BD). Herre s.n.

in SUG 14693 (BOL); Cornellskop (-BD), Wisura 1579 (NBG).

The relatively short internodes sheathed by the

leaves for half their length, and the long narrow

leaves distinguish this species from others of the

genus. The distribution of this species is shown in

Figure 9.

FIGURE 9. — Distribution of Astridia herrei, ▲ ; and Acrodon

duplessiae, •.

1.4 Astridia citrina (L. Bol.) L. Bol. in Journal

of South African Botany 32: 230 (1966b); Jacobsen:

413 (1974). Glen: t. 1917 (1985). Type: SWA/Nami-

bia, without precise locality, cultivated in Windhoek

Government Garden, July-August 1937, Rusch &

Erni sub Holloway 58 (BOL!).

A. rubra (L. Bol.) L. Bol. var. citrina L. Bol.: 170 (1961b).

Bothalia 16,2 (1986)

211

Robust shrubs 300-400 mm tall. Stems pale buff to

dark brown when young; internodes ± 20 x 5,5 mm.

Leaves minutely velutinous, 30-55 (-70) mm long,

strongly keeled, 11-19 mm thick. Pedicel ± 13 x 3

mm. Bracts up to 19 mm long and 10 mm thick.

Flower ± 50 mm in diameter when open. Sepals 6,

outer pair up to 12 x 8 mm, inner 4 up to 11 x 7

mm. Petals ± 50 in 1-2 series, white to yellow, 18-23

x up to 3 mm. Staminodes present, 6-9 mm long,

distinct from petals. Stamens many; filaments 4-9

mm long. Stigmas subulate to filiform, shorter or

longer than longest stamens, 8,5-11 mm long. Cap-

sule dark grey, broadly obconical, ±11,5 mm in di-

ameter when closed and 10 mm long; valve wings

absent; placental tubercles small, radial diameter 0,5

mm. Seeds deep maroon, echinate, 1,1-14 x

0,75-1,05 x 0, 5-0,9 mm, micropylar region 0,3-0,55

mm long; baculae prominent, more so on micropylar

region than embryo region; microbaculae large, el-

liptical-conical.

Voucher specimens:

SWA/NAMIBIA. — 2816 (Oranjemund): Rooilepel (-BA),

Hardy 4826 (PRE); Lorelei (-BB), Giess, Volk & Bleissner 5421

(WIND).

The yellow colour of the flowers in this species is

unique in the genus. Other distinguishing characters

are the combination of wide and deep leaves relative

to their length, relatively long pedicels and long cap-

sules. The distribution of this species is shown in Fig-

ure 10.

FIGURE 10. — Distribution of Astridia citrina, ☆; A. speciosa,

• ; Acrodon leptophyllus, ▲; and Ebracteola wilmaniae,

1.5 Astridia speciosa L. Bol. in Journal of South

African Botany 27: 111 (1961c); Jacobsen: 413

(1974). Type: SWA/Namibia, 5 miles north of Sen-

delingsdrift, March 1960, H. Hall 1869 (BOL!).

Shrublets ± 200 mm tall and in diameter.

Branches with internodes ± 25 x 5 mm when young.

Leaves velvety, 20-63 mm long, 7-22 mm wide and

thick, obscurely keeled, sheathing stem for ± 5 mm.

Pedicels very short. Bracts up to 13 mm long and 8

mm thick. Flowers ± 70 mm in diameter when open.

Sepals 6, outer pair up to 9 x 6,5 mm, inner 4 up to 8

x 4 mm. Petals many, red-orange, (23-) 25-33 x up

to 3,5 mm, grading into staminodes. Staminodes

11-12 mm long. Stamens very many; filaments 5,5-9

mm long; anthers and pollen golden. Stigmas fili-

form, (9-) 10-11 mm long, overtopping stamens.

Capsule and seeds not seen.

Voucher specimens:

SWA/NAMIBIA. — 2816 (Oranjemund): north of Sendelings-

drift (-BB), H. Hall 1869 = NBG 175160 (BOL); Kahans Mine

(-BB), Rusch sub Dinter 8394 (B).

The flowers of this species are the largest and

showiest in the genus. Like A. vanheerdei, to which

it is very similar, it may be distinguished from A.

longifolia by its subsessile flowers (and, presumably,

capsules). It is similar to A. longifolia and different

from A. vanheerdei in the narrowing of the leaf bases

and the presence of staminodes. These three species

are very close, and still more detailed studies may

show that they are all one species. The distribution

of this species is shown in Figure 10.

1.6 Astridia hallii L. Bol., Notes on Mesem-

bryanthemum and allied genera 3: 298 (1958); Ja-

cobsen: 413 (1974). Type: SWA/Namibia, Lorelei

opposite Sendelingsdrift, July 1955, H. Hall s.n. in

NBG 489/55 (BOL!).

A. ruschii L. Bol.: 169 (1961b); Jacobsen: 413 (1974); Glen t.

1894 (1984). Type: SWA/Namibia, without precise locality, culti-

vated in Windhoek Government Garden, July-August 1937,

Rusch & Erni sub Holloway 24 (BOL!).

Robust shrubs 200-300 mm tall. Stems pale buff

when young; internodes ± 30 mm long and 8 mm in

diameter. Leaves glaucous, triquetrous, keeled,

42-78 (-118) mm long, (4-) 14-20 mm wide and

thick, minutely velutinous, sheathing stem for ± 7

mm. Pedicels ± 13 x 4 mm. Bracts up to 24 mm long

and 11 mm thick. Flower ± 60 mm in diameter when

open. Sepals 6, outer pair up to 13 x 12 mm, inner 4

up to 10 x 6 mm. Petals ± 70, white or rarely pale

pink, 22-36,5 x up to 3 mm. Staminodes absent. Sta-

mens many, 3,5-11 mm long. Stigmas filiform, 4-11

mm long. Capsule broadly obconical, ± 13,5 mm in

diameter when closed and 9,5 mm long; covering

membranes present, covering most of interior; valve

wings present or absent, if present then long and

awn-like; placental tubercles large, radial diameter

± 1,4 mm; expanding keels slightly to widely diverg-

ing. Seeds medium brown to dark maroon, 0,95-1,5

x 0,7-l,0 x 0,6-0, 9 mm, micropylar region 0,3-0,55

mm long; baculae prominent, more so on embryo

region than on micropyle; microbaculae conspicu-

ous, long, cylindrical to elliptical.

Voucher specimens:

SWA/NAMIBIA. — 2715 (Bogenfels): Schlafkuppe (-BD),

Hardy 4636 (PRE). 2716 (Witputs): 41 miles south of Witputs

(-DD), Littlewood s.n. in KG 756161 (M). 2816 (Oranjemund):

Kahanstal (-BB). Dinter 8186 (B. K); Lorelei (-BB), H. Halls, n.

in NBG 489155 (BOL).

As will be seen from the scatter diagram in Figure

11, Astridia ruschii is quite indistinguishable from A.

hallii in leaf characters. The same is true for all other

characters examined. These two names must there-

fore be regarded as referring to the same species.

212

Bothalia 16,2 (1986)

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Le af length, mm

FIGURE 11. — Leaf measure-

ments of plants included in

Astridia hallii.

FIGURE 12. — Distribution of Astridia hallii, A ; and Ebracteola

fulleri, #.

The relatively wide leaves, long pedicels and

broad, shallow capsules distinguish this species from

all others. The distribution of this species is shown in

Figure 12.

1.7 Astridia vanheerdei L. Bol. in Journal of

South African Botany 28: 219 (1962a); Jacobsen:

414 (1974). Type: Cape, between Annisfontein and

Bloeddrift, April 1962, P. van Heerde s. n. in NBG

251/62 (BOL!).

Robust shrubs ± 200 mm tall. Stems pale buff

when young; internodes ± 27 mm long and 5 mm in

diameter. Leaves glaucous, triquetrous, keeled,

38-57 (-65) mm long, 10-13 (-14,5) mm wide and

16-21 (-23) mm thick, minutely velutinous, sheath-

ing stem for ± 7 mm. Pedicels very short. Bracts up

to 17 mm long and 8,5 mm thick. Flowers ± 50 mm

in diameter when open. Sepals 6, outer pair up to 12

x 8 mm, inner 4 up to 10 x 6 mm. Petals ± 70, ma-

genta-red, 19-20 x up to 2 mm. Staminodes absent.

Stamens many, 4-9 mm long. Stigmas filiform, 6-7

mm long. Capsule and seeds not seen.

Voucher specimen:

CAPE. — 2816 (Oranjemund): between Annisfontein and

Bloeddrift (-BD), P. van Heerde s.n. in NBG 251162 (BOL).

This species differs from A. longifolia in the rela-

tively broad leaf-bases, the subsessile flowers and

the absence of staminodes. The first of these charac-

ters distinguishes it from A. speciosa, as do the lat-

erally compressed leaves and the absence of stami-

nodes. The distribution of this species is shown in

Figure 13.

This species is known only from the type speci-

men, and so must be regarded as the rarest and least-

known member of this genus.

FIGURE 13. — Distribution of Astridia vanheerdei, A: and

Ebracteola montis-moltkei, 0.

Excluded species

Astridia maxima (Haw.) Schwant. in Zeitschrift

fur Sukkulentenkunde 3: 16 (1927). This is based on

Mesembryanthemum maximum Haw., and is cor-

rectly called Ruschia maxima (Haw.) L. Bol.

2. ACRODON

Acrodon N.E. Br. is a genus of four rather similar-

looking species of dwarf habit. Two of these species

have, until now, been included in Ruschia, and the

arrangement of specimens in BOL indicates that L.

Bolus and her co-workers were in some doubt as to

whether these two genera should be retained or

merged into one. Ruschia is regarded here as a genus

of typically shrubby plants, most of which have flow-

ers in cymose inflorescences. Only in the section Un-

cinata does one find plants in which the leaf keel is

toothed; these plants are shrubs with leaves decur-

rent on the internodes, and flowers with petals of

uniform colour, often arranged in five ‘fascicles’.

Bothalia 16,2 (1986)

213

1.3

1.2

1.0

bellidiflorus var.

bellidiflorus

bellidiflorus var

viridis

bellidiflorus var.

st rial us

subulatus

0.9

— parvifolius

07

FIGURE 14. — Phenogram of Acrodon calculated from a distance matrix using UPGMA. Irrelevant OTU’s are omitted.

bellidiflorus var.

bellidiflorus

bellidiflorus var.

viridis

bellidiflorus var.

striatus

subulatus

parvifolius

0.1

0.2 l

0 4

0.5

0.7

FIGURE 15. Phenogram of Acrodon calculated from a correlation matrix using UPGMA. Irrelevant OTU’s are omitted.

The leaves of Acrodon are longer and wider than

those of Ruschia section Uncinata, and dark green

rather than greyish. The flowers of Acrodon are soli-

tary, and the petals are evenly spaced. They are

characterized by a central longitudinal stripe of a

darker colour than the rest of the petal. Acrodon is

therefore among the more distinctive genera in the

family Mesembryanthemaceae.

It may be distinguished from Ruschia section Un-

cinata not only on morphological but also on geo-

graphical grounds. Ruschia section Uncinata is

characteristically found in the upper Karoo and

SWA/Namibia, with outlying species in the Orange

Free State and western Transvaal, while Acrodon is

restricted to the southern Cape and Little Karoo, in

Acocks’s (1975) Fynbos, Coastal Rhenosterbosveld,

Coastal Macchia, Succulent Mountain Scrub and

Karroid Broken Veld types.

Plants of this small genus were among the first

highly succulent members of the family Mesem-

bryanthemaceae to become known in Europe. Acro-

don bellidiflorus was well known in England (Brad-

ley 1717; Dillenius 1731) and the Netherlands (Lin-

naeus 1738; Van Royen 1740) early in the eighteenth

century. It appears that this species was introduced

into cultivation, at least in England and Germany, as

early as the end of the seventeenth century, as the

first descriptions of it date from 1700 (Plukenet

1700; Volckamer 1700). Linnaeus evidently knew

the plant from his period of work at Clifford’s gar-

den near Leyden in the Netherlands. His descrip-

tions in the Hortus Cliffortianus and the Species

Plantarum (1753) make use of the sharply trique-

trous leaves and the small teeth on the leaf keel near

the apex; these characters are still used to distinguish

Acrodon from others of the family. Haworth (1821)

distinguished two varieties of A. bellidiflorus. The

genus Acrodon was separated from Mesembryanthe-

mum L. by N. E. Brown (1927), who at that time

included only A. bellidiflorus in his new genus.

The classification presented here is based on the

phenograms shown in Figures 14 & 15. The great

similarity between species of Acrodon is shown by

the scatter diagrams in Figures 17-19. From these it

can be seen that the species are difficult to separate

reliably on the basis of individual characters taken

pairwise and plotted on scatter diagrams, but that

multivariate methods using as many characters as

possible together, not just two at a time, distinguish

more certainly between very close species.

Acrodon N. E. Br. in Gardeners’ Chronicle, series

3, 81: 12 (1927); Herre: 62 (1971); Dyer: 95 (1975).

Type species: A. bellidiflorus (L.) N. E. Br.

Dwarf succulents with internodes completely hid-

den by leaf bases. Leaves bright green, sharply tri-

quetrous, often with a few small teeth on keel near

apex. Flowers solitary; pedicels with leaf-like bracts.

Sepals 5, in two series, outer pair fleshy, inner 3 less

so, with membranous margins and generally signifi-

cantly smaller. Petals 30 or more, 1-3-seriate, white

to pink, usually with conspicuous darker pink to ma-

genta longitudinal stripes. Staminodes present or ab-

sent. Stamens numerous, erect; filaments papillate at

least at base. Stigmas 5, subulate. Capsules relatively

large, turbiniform, woody, 5-locular; covering mem-

branes well developed; valve wings awn-like, rarely

absent; placental tubercles relatively large. Seeds

various shades of maroon to black, with conspicu-

ous, well spaced baculae on the embryo region.

KEY TO THE SPECIES OF ACRODON

la Leaves laterally compressed (thickness greater than breadth):

2a Plants creeping; leaves less than 20 mm long; fruit usually less than 9 mm in diameter; pedicels ± 14

mm long 2. A parvifolius

2b Plants erect; leaves more than 30 mm long, usually much longer; fruit more than 10 mm in diameter;

pedicels 27-58 mm long 4. A. leptophyllus

lb Leaves dorsally compressed (breadth greater than thickness) or not compressed (thickness equal to

breadth):

3a Leaves with marginal as well as dorsal teeth, glaucous green 3 .A. duplessiae

3b Leaves only with dorsal teeth, glaucous to bright green:

4a Leaves bright green; capsule no more than ! as long as in diameter 1. A. bellidiflorus

4b Leaves glaucous green; capsule almost as long as in diameter 4. A. leptophyllus

214

Bothalia 16,2 (1986)

2.1 Acrodon bellidiflorus (L.) N. E. Br. in Gar-

deners’ Chronicle, series 3, 81: 12 (1927); Jacobsen:

404 (1974).

Meserribryanthemum bellidiflorum L.: 484 (1753); DC.: 424

(1828); Salm Dyck: § 12: t. 1 (1836-63; published 1840). Icono-

type: Meserribryanthemum bellidiflorum Dill.: 244 t. 189 fig. 233

(1731).

M. subulatum Mill.: n. 10 (1768). M. bellidiflorum L. var. subu-

latum (Mill.) Haw.: 106 (1821); DC.: 424 (1828); Salm Dyck: § 12

t. ly (1836-63; published 1840); Berger: 221 (1908). A. subulatus

(Mill.) N. E. Br. : 77 ( 1928); Jacobsen: 404 (1974). Type not cited.

M. bellidiflorum L. var. glaucescens Haw.: 106 (1821); DC.:

424 (1828). Iconotype: Dillenius: fig. 233 (1731).

M. bellidiflorum L. var. simplex DC.: t. 41 (1798-1837; pub-

lished 1799). Type not cited.

M. bellidiflorum L. var. viride Haw.: 106 (1821); DC.: 424

(1828); Salm Dyck: § 12: t. IB (1836-63; published 1840); Berger:

221 (1908). Type not cited.

Ruschia longifolia L. Bol.: 500 (1928-35; published 1935); Ja-

cobsen: 556 (1974). Type: Cape, Huis River Pass, November

1933, Herre s.n. in SUG 10234 (BOL!).

Pre-Linnaean citations:

Ficoides africana mesembrianthemum triquetro folio, flore

albo, parvo, polyanthos, Plukenet: 77 (1700); Ray: 364 n. 2

(1704).

Ficoides africana humilis, folio triangulari breviori nonnihil

spinoso seu denticulato, Volckamer: 166 (1700). Ficoides seu fi-

cus aizoides africana folio triangulari crasso brevi glauco ad tres

margines aculeata, Boerhaave 1: 290 n. 21 (1720).

Dwarf succulents; internodes hidden by leaf

bases. Leaves bright green, triquetrous, not com-

pressed, 14-54 (-80) mm long, 2-8 (-10) mm wide

and thick, with a number of small teeth on apical end

of keel. Pedicels ± 38 x 1,5 mm, with a pair of

bracts near base, these leaf-like, up to 22 mm long

and 4,5 mm thick. Flowers ± 35 mm in diameter

when open. Sepals 5, in two series, outer pair nar-

rowly deltoid, up to 12 x 8 mm, inner 3 broadly del-

toid to almost rectangular, up to 8 x 6 mm. Petals ±

40-60, 2-seriate, white or pale pink with a central

magenta stripe and magenta margins and apices,

these usually obtuse, 7-19 x up to 3 mm. Stami-

nodes usually absent, if present then 4—5,2 mm long,

white with pink apices, sharply distinct from petals.

Stamens numerous; filaments 1-6 mm long, papillate

at base, innermost filaments papillate in lower half;

anthers magenta; pollen white. Stigmas 5, broadly

subulate, 1-4 mm long. Capsule 9 x ± 11 mm; cov-

ering membrane covering most of interior; valve-

wings present or absent, when present awn-like; pla-

cental tubercles large, radial diameter 1-1,5 mm; ex-

panding keels narrowly diverging or almost parallel,

fringed with small papillae or unadorned. Seeds dark

maroon, 0,96-1,55 x 0,81-1,14 x 0,49-1,07 mm,

micropylar region 0,32-0,67 mm long; baculae hemi-

spherical-cylindrical, well spaced, almost as well de-

veloped on micropylar region as on embryo region;

FIGURE 16. — SEM photographs of seeds of A, Acrodon bellidiflorus; B, A. parvifolius; C, A. duplessiae; D, A. leptophyllus.

Scale bar= 100pm.

Bothalia 16,2 (1986)

215

microbaculae rod-shaped, conspicuous. Chromo-

some number 2n = 18 (Riley & Hoff 1961). Figures

16-19.

Voucher specimens:

CAPE. — 3318 (Cape Town): Kalabaskraal (-DA), L. Bolus

s.n. in NBG 880115 (K). 3320 (Montagu): Barrydale (-DC) Muir

s.n. (K), Compton & Cook s.n. in NBG 1992123 (BOL). 3321 (La-

dismith): Huis River Pass (-BC) Herre s.n. in SUG 10234 (BOL),

Herre s.n. in SUG 11601 (BOL).

A. bellidiflorus differs from A. parvifolius in that

the former species grows in small tufts of long leaves

and has large flowers and relatively larger fruits. A.

parvifolius grows in large mats with trailing stems

bearing short, wide leaves, small flowers and rela-

tively small fruits. The leaves of A. duplessiae have

marginal teeth, are glaucous green and are dorsally

compressed, while those of A. bellidiflorus have

teeth only on the keel, and are bright green and sym-

# - R. belltdtflorue

0 - R. parvl -fo 1 1 us

+ ° R . dup 1 ©ss 1 a©

0 - R. leptophyllus

j %■

^® H

S

+» ®

e

f ®

o » ^ ®-®»* $

* ® ® *

® ®* *e * *jg* ®

tfo°

0

0 10 20 30 40

Le af length, mm

R . be 1 1 1 d 1 f 1 o rus

FIGURE 17. — Leaf measure-

ments of Acrodon spp.

' r

L

6 L

L

5 L

L

4 L

L

3 L

L

2 L

L

i L

L

R. bet li d t f torus

R . parvifolius

R. duplessiae

R. 1 optophy I 1 us

+«

*

® « U

0 « ®

8 «

+ *

o • **

0

Pedicel length, mm

60

70

FIGURE 18. — Pedicel measure-

ments of Acrodon spp.

216

Bothalia 16,2 (1986)

5 L »

0

L +

H. bell Idlf lorue

R. djplosslae

fl. leptophyllue

4 L

*

L

3 L

Filament length, mm

FIGURE 19. — Stigma and sta-

men measurements of Ac-

rodon spp.

metrical in transverse section. Capsules of A. duples-

siae are generally slightly broader in relation to their

depth than those of A. bellidiflorus, and seeds are

smaller and darker in colour. A. leptophyllus also

has glaucous leaves, but these tend to be longer than

those of A. bellidiflorus. The capsules of A. lepto-

phyllus are significantly longer relative to their di-

ameter than those of A. bellidiflorus.

No individual character or group of characters can

be used to distinguish between specimens hitherto

assigned to A. bellidiflorus, A. subulatus and Rus-

chia longifolia (cf. Figure 20). It is therefore neces-

sary to regard these three names and their nomen-

clatural synonyms as referring to the same species,

the correct name being A bellidiflorus. The distribu-

tion of this species is shown in Figure 6.

2.2 Acrodon parvifolius R. du Plessis in Notes

on Mesembryanthemum and allied genera 3: 386

(1958); Jacobsen: 404 (1974). Type: Cape, between

Hawston and Hermanus, October 1955, R. du Ples-

sis 164 (BOL!).

T

# “ R. be II Id t f lorua

0 “ R. subu 1 atus

9 L

^ + - R. 1 ong t f o If a

8 L *

tt

4

M

Le af length, mm

*

*

t*

*

60 70 80 90 100

FIGURE 20. — Leaf measure-

ments of A. bellidiflorus, * ;

‘A. subulatus', O', and ‘Rus-

chia longifolia’, +.

Bothalia 16,2 (1986)

2)7

Creeping, succulent-leafed herbs forming mats up

to 1 m in diameter. Stems with internodes not com-

pletely hidden by leaf bases; young internodes, when

visible, pale brown and shiny. Leaves bright green to

olive green, reddish brown at apices, laterally com-

pressed, sharply triquetrous, 13-17,5 mm long, 2-3

(-4) mm wide and 2,5-5 mm thick, with a few small

teeth on keel at apex. Pedicels ± 14 mm long and

slightly over 1 mm in diameter, with a pair of leaf-

like bracts at base. Flowers opening about midday,

small for genus, 17-20 mm in diameter when open.

Sepals 5, in two series, outer pair up to 5 x 4 mm,

inner 3 up to 4 x 3 mm. Petals ± 35, white to pink,

with a central longitudinal pink to magenta stripe

and magenta margins, 6-8 x 1 mm. Staminodes few,

sharply distinct from petals, white with pink apices,

3, 5-4, 5 mm long. Stamens in several series; fila-

ments papillate at base or in lower half, pink, 2-3

mm long; anthers deep purple; pollen pink. Stigmas

subulate, pink. Capsule 6,5 x ± 8,5 mm; covering

membranes covering most of the interior; valve

wings awn-like; placental tubercles small, radial di-

ameter ± 0,8 mm; expanding keels almost parallel,

unadorned. Seeds deep brown, 0,7-0, 9 (-1,0) x

0,6-0, 7 x 0,45-0,65 mm, micropylar region

0,22-0,38 mm long; baculae large, hemispherical-

cylindrical and well spaced on embryo region, less

regular on micropylar region; microbaculae rod-

shaped, conspicuous.

Voucher specimen:

CAPE. — 3419 (Caledon): between Hawston and Hermanus

(-AC), R. du Plessis 164 (BOL).

Individual differences between this species and A.

bellidiflorus are dealt with under that species. The

coastal habitat (Figure 8) of this species may be a

useful character in distinguishing between A. parvi-

folius on the one hand and A. duplessiae and A. lep-

tophyllus on the other.

2.3 Acrodon duplessiae (L. Bol.) Glen , comb.

nov.

Ruschia duplessiae L. Bol.: 431 (1928-35; published 1934); Ja-

cobsen: 551 (1974). Type: Cape, near Oudtshoorn, June-July

1933, R. du Plessis s.n. in NBG 1048132 (BOL!).

Dwarf succulents; internodes hidden by leaf

bases. Leaves glaucous green, triquetrous, dorsally

compressed, 20-61 mm long, 7-16 mm wide and half

as thick, with a number of small teeth on margins

near apex, as well as on apical end of keel. Pedicels

about 40 mm long, with a pair of bracts near base,

these leaf-like, up to 26 mm long and 4 mm thick.

Flowers ± 35 mm in diameter when open. Sepals 5,

in two series, outer pair narrowly deltoid, up to 12 x

7,5 mm, inner 3 broadly deltoid to almost rectangu-

lar, up to 7,5 x 5,5 mm. Petals ± 45, 3-seriate, white

or pale pink with a central magenta stripe and ma-

genta margins and apices, these usually emarginate,

rarely obtuse, (11,5-) 13-21 x 3 mm. Staminodes

absent. Stamens numerous; filaments pink, 2, 5-5, 5

mm long, papillate at base, innermost filaments pa-

pillate in lower half; anthers magenta; pollen white.

Stigmas 5, broadly subulate, 2-3 mm long. Capsule 9

x ± 12 mm; covering membranes covering most of

interior; valve-wings awn-like; placental tubercles

large, radial diameter 1,4 mm; expanding keels

widely diverging, fringed with small papillae. Seeds

very dark maroon to black, 0,9-1 ,2 x 0,61-0,73

(-0,80) x 0,53-0,65 (-0,71) mm, micropylar region

0,34-0,47 mm long; baculae large, hemispherical-

cylindrical, well spaced, almost as well developed on

micropylar region as on embryo region; microbacu-

lae rod-shaped, conspicuous.

Voucher specimens:

CAPE. — 3321 (Ladismith): Huisrivierberg (-BC/DA), Herre

s.n. in SUG 11608 (BOL). 3322 (Oudtshoorn): near Oudtshoorn

(-CA), R. du Plessis s.n. in NBG 1048/32 (BOL); Robinson Pass

(-CC), /. de Jagers.n. in BOL 24718 (BOL). 3421 (Riversdale):

Melkhoutfontein (-AD), L. Bolus s.n. (BOL).

Differences between A. duplessiae on the one

hand and A. bellidiflorus and A. parvifolius on the

other are discussed under those species. Leaves of

A. duplessiae are generally much broader and

slightly shorter than those of A. leptophyllus; they

also have marginal teeth, which are lacking in the

latter species. In A. duplessiae the petals are some-

what longer than in A. leptophyllus, and the capsules

are shallower in relation to their diameter. Distribu-

tion of this species is shown in Figure 9.

2.4 Acrodon leptophyllus (L. Bol.) Glen, comb.

nov.

Ruschia leptophylla L. Bol.: 333 (1928-1935; published 1932);

Jacobsen: 555 (1974). Type: Cape, Hermanus, August-Sep-

tember 1931, H. L. de Villiers s.n. in NBG 958/31 (BOL!).

R. macrophylla L. Bol.: 351 (1928-1935; published 1932); Ja-

cobsen: 556 (1974). Type: Cape, near MacGregor, July 1929, R.

H. Compton s.n. in NBG 1188/24 (BOL!).

R. constricta L. Bol.: 496 (1928-1935; published 1935); Jacob-

sen: 549 (1974). Type: Cape, near Bredasdorp, April 1933, L.

Bolus s.n. in NBG 718133 (BOL!, holo.; K!, iso.).

Dwarf succulents; internodes hidden by leaf

bases. Leaves glaucous green, triquetrous, dorsally,

laterally or not compressed, 15-75 (-102) mm long,

2, 2-9, 8 (-12,5) mm wide and half to twice as thick,

with a number of small teeth on apical end of keel.

Pedicels ± 34 x 2 mm, with a pair of bracts near

base, these leaf-like, up to 27 mm long and 5 mm

thick. Flowers ± 30 mm in diameter when open. Se-

pals 5, in two series, outer pair narrowly deltoid, up

to 12 x 7,5 mm, inner 3 broadly deltoid to almost

rectangular, up to 9,5 x 7,5 mm. Petals 45-60, 2-se-

riate, white or pale pink with a central magenta

stripe and magenta margins and apices, these usually

emarginate, rarely obtuse, 8-17 x ± 2 mm. Stami-

nodes usually absent, if present then (2-) 3-5 mm

long, distinct from petals, white with pink apices.

Stamens numerous; filaments pink, (1,5-) 2, 5-5,5

mm long, papillate at base, innermost filaments pa-

pillate in lower half; anthers magenta; pollen white.

Stigmas broadly subulate, 1-3,5 mm long. Capsule

11 x ±12 mm; covering membranes covering al-

most all of interior; valve-wings awn-like, rarely ab-

sent; placental tubercles large, radial diameter 1,5

mm; expanding keels almost parallel, fringed with

small papillae or unadorned. Seeds maroon to black,

I, 00-1,50 x 0,84-1,10 x 0,75-0,97 (-1,04) mm,

micropylar region 0,39-0,68 mm long; baculae hemi-

spherical-cylindrical, well spaced, almost as well de-

218

Bothalia 16,2 (1986)

veloped on micropylar region as on embryo region;

microbaculae rod-shaped, conspicuous.

Voucher specimens:

CAPE. — 3319 (Worcester): Villiersdorp (-CD), Middlemost

s.n. in NBG 2703/27 (BOL); MacGregor (-DD), Compton s.n. in

NBG 1188/24 (BOL), Leipoldts.n. (BOL). 3320 (Montagu): Bar-

rydale (-DC), E. Esterhuysen s.n. (BOL). 3321 (Ladismith):

mountains facing karoo, Riversdale Div. (-CC/CD), Ferguson

s.n. in NBG 1296/27 (BOL).

Differences between this species and others in the

genus are discussed above, under the species con-

cerned. Distribution of this species is shown in Fig-

ure 10.

The name ‘Ruschia leptophylla' was published in a

fascicle of Notes on Mesembryanthemum and allied

genera dated 29th January 1932, while the fascicle in

which the name ‘R. macrophylla' was published is

dated 24th June 1932. The reason for choosing the

epithet leptophylla rather than macrophylla for this

species, therefore, rests on consideration of a prior-

ity of about six months.

The only difference between plants identified as

Ruschia macrophylla and those previously called R.

leptophylla and R. compressa is in the ratio of leaf

thickness to leaf length, and even in this character

there is a small degree of overlap (Figure 21). In all

other measured characters the overlap is complete

(see, for example. Figures 18 & 19), and the states of

‘multi-state’ characters are the same for all the taxa

included in the present species. For this reason the

taxa united here are not retained as separate species.

3. EBRACTEOLA

This genus comprises five remarkably similar-

looking species. They are readily distinguished from

most genera in the subtribe Ruschiinae by their

dwarf habit, leaves without teeth and petals without

longitudinal stripes, and from most Mesembryanthe-

maceae of dwarf habit by their thickened, woody

rootstocks. The whitish colour of the seeds and the

absence of bracts are useful accessory characters but

do not appear in all species of Ebracteola.

The first species of Ebracteola Dinter & Schwant.

to become known was described under the name

Mesembryanthemum wilmaniae from near Kimber-

ley (Bolus 1916). This was followed by M. montis-

moltkei from the other extremity of the range of this

genus, near Windhoek (Dinter 1922), M. derenber-

gianum in the following year (Dinter 1923), Ruschia

fulleri a few years later (Bolus 1929) and finally,

after a thirty-year interval, Ebracteola Candida (Bo-

lus 1961a). The genus was first described to accom-

modate M. montis-moltkei and M. derenbergianum

(Dinter & Schwantes 1927).

Apart from Friedrich’s (1970) study of the

SWA/Namibian material, no critical study of the

genus has been published until now. Three species of

the genus were examined in the course of a study of

the subtribe Lampranthinae (Glen 1978), but the

only conclusion to be drawn at that time was that

Ebracteola was not a member of that subtribe, and

was probably better placed in the subtribe Ruschii-

nae.

The generic name refers to the absence of bracts

in most specimens of these two species, with a dimin-

utive ending to indicate the dwarf habit of plants of

this genus.

The phenograms used to generate the classifica-

tion presented here are shown in Figures 22 & 23.

The great similarity between the different species of

Ebracteola is shown graphically by the scatter dia-

grams in Figures 24-26. From these it can be seen

that the species are difficult to separate reliably on

the basis of character pairs plotted on scatter dia-

grams, but that multivariate methods using as many

characters as possible together, not just two at a

time, distinguish more certainly between very close

species.

The protologue of the genus does not indicate

which of the two first-accepted species was to be

* ■ R. 1 eptophy I 1 a

0 - R. macrophylla

+ - R. constrlcta

e

E

.c

+>

T>

3

4-

(0

(D

10.

0 1

6 -

4 1

2 1

0

0

0

0

0

0 i I 1 , I i J i I j I j I i I i I i 1 1 1

0 10 20 30 40 50 60 70 00 90 100 110

Le af length, mm

FIGURE 21. — Leaf measure-

ments of A. leptophyllus.

Bothalia 16,2 (1986)

219

taken as the type of the genus. The choice of E.

montis-moltkei (Dinter) Dinter & Schwant. was

made by Von Poellnitz (1933: 40), without any

reason being given. This choice must necessarily be

followed, but it may be pointed out that the other

species placed in their new genus by Dinter &

Schwantes, E. derenbergiana (Dinter) Dinter &

Schwant., was alone transferred from Ebracteola to

Ruschia by Bolus (in Jacobsen 1955) and Weber

(1968).

The species here transferred to Ebracteola from

Ruschia, namely E. wilmaniae and E. fulleri, are

dwarf cushion-forming succulents with essentially

semiterete leaves, although forms of E. wilmaniae

with sharply triquetrous leaves are known. They also

have solitary flowers which are very similar to each

other and to other species previously included in

Ebracteola. These characters are rare in the Ruschii-

nae, and so these species were found to be closer to

other species classified under Ebracteola than to any

species of Ruschia, regardless of which measure of

similarity was used. For this reason they are transfer-

red from Ruschia to Ebracteola.

other genera

1,15

Candida

renniei

wilmaniae vat.

wilmaniae

wilmaniae vat.

augustilolia

wilmaniae var.

vermeuleniae

— — montis-moltkei

1,05 0,95 0,85 0,75 0,65

FIGURE 22. — Phenogram of Ebracteola calculated from a distance matrix using UPGMA. Irrelevant OTU’s are omitted.

FIGURE 23. — Phenogram of Ebracteola calculated from a correlation matrix using UPGMA. Irrelevant OTU’s are omitted.

£

E

_r

+>

■o

3

M-

10

<a

«

o

+

e

X

7 L

6 L

5 L

4 L

3 L

2 L

10r

9 L

8 L

E. uit 1 man t as

E. fuller!

E. candtda +

E. derenbergiana

E. mont t e-mo 1 tko 1

X +

X X

X X * 4 * «

It

It + X

0

i L

0L ^ L L ^ L_ . — 1 — 1 — I —

0 10 20 30 40 50

Leaf length, mm

it

FIGURE 24. — Leaf measure-

ments of all species of

Ebracteola.

Seed width, mm Capsule length, mm

220

Bothalia 16,2 (1986)

llL

i

10L

L

9 L

L

8 L

L

7 L

L

G L

L

5 L

L

4 L

L

3 L

L

2 L

L

1 L

*

0

+

«

X

E. u>1 1 man 1 ae

E. f u 1 1 on t

E. Candida

E. doponborg I ana

E. mont t»-mo 1 tko I

»

a

a

«

X

X

s

XX 0

XXX

X

*

X

a

l_i—L i_l_

0123456789

Capsule diameter, mm

FIGURE 25. — Capsule measure-

ments of all species of

Ebracteola.

1 •|L

L

1 L

L

.9L

L

.eL

L

•7L

L

.gL

L

. sL

L

.4L

L

. 3L

L

• 2L

a - E. wl I man 1 ae

0 - E. fuller!

+ “ E. Candida

# " E. derenberg 1 ana

X - E, mont 1 a-mo 1 tko 1

I-

4

0 i_ i_ , 1 j 1 . -i

0 .1 .2 .3 .4

Seed length, mm

X

x

.5

*#

* a

+ . *

«« ®0 a *

1 % \

I I I — I I — ! — L~ u-

.6 .7 .0 .9

FIGURE 26. — Seed measure-

ments of all species of

Ebracteola.

Bothalia 16,2 (1986)

221

Ebracteola Dinter & Schwant. in Zeitschrift fur

Sukkulentenkunde 3: 24 (1927); Friedrich: 44

(1970); Herre: 146 (1971); Dyer: 110 (1975). Lecto-

type species: E. montis-moltkei (Dinter) Dinter &

Schwant. (cited by Von Poellnitz 1933: 40).

Dwarf clump-forming succulents with strongly en-

larged, caudiciform rootstocks and internodes com-

pletely hidden by leaf bases. Leaves elongate, tri-

quetrous to terete, without teeth, glabrous, apple-

green to glaucous, yellowish or reddish. Flowers usu-

ally solitary, rarely ternate; pedicels with 2 bracts, or

bracts absent. Sepals 5, in two series, outer pair

fleshy, inner 3 slightly smaller, with membranous

margins. Petals ± 25-60, in 1-2 series, lorate, nar-

rowly oblanceolate or narrowly obovate. Staminodes

present. Stamens many, erect. Stigmas 5, subulate.

Capsules turbinate, grey, woody, 5-locular; covering

membranes well developed; valve wings absent or if

present then awn-like to wing-like; placental tuber-

cles usually present, rarely absent. Seeds small,

cream to maroon, with distinct baculae. Figure 27.

FIGURE 27. SEM photographs of seeds of A, Ebracteola candida\ B, E. fulleri\ C, E. renniei ; D, E. derenbergiana ,

E, E. wilmaniae; F, E. wilmaniae ‘var. augustifolia'. Scale bar= 100pm. B, x 90.

222

Bothalia 16,2 (1986)

KEY TO THE SPECIES OF EBRACTEOLA

la Leaves sharply triquetrous:

2a Flowers ± 30 mm in diameter; capsules 8-9 mm in diameter and 6-7 mm long; bracts present; petals

white to pale pink; plants found in the northern Cape and western Transvaal 1. E. wilmaniae

2b Flowers ± 25 mm in diameter; capsules 6-7 mm in diameter and 4-5 mm long; bracts absent; petals

bright magenta-pink; plants found in SWA/Namibia (Windhoek District) 5. E. montis-moltkei

lb Leaves obscurely triquetrous to almost terete:

3a Bracts absent; flowers ± 20 mm in diameter; petals bright pink 4. E. derenbergiana

3b Bracts present; flowers 25-30 mm in diameter; petals white to pale pink:

4a Bracts scale-like, not over 5 mm long; leaves 13-28 mm long, 2-4 mm wide and thick; petals pale

pink 2. E. fallen

4b Bracts leaf-like, 8 mm long or longer; leaves 9-60 mm long, 2-7,5 mm wide and thick; petals white

to pale pink:

5a Flowers often ternate; found in SWA/Namibia (Liideritz District); leaves thicker than

wide 3. E. Candida

5b Flowers solitary; found in the northern Cape and western Transvaal; leaves wider than thick or

equally wide and thick 1. E. wilmaniae

3.1 Ebracteola wilmaniae (L. Bol.) Glen , comb.

nov.

Mesembryanthemum wilmaniae L. Bol.: 28 (1916). Ruschia wil-

maniae (L. Bol.)L. Bol.: 158 (1928-1935; published 1929); Jacob-

sen: 566 (1974). Syntypes: Cape, Papkuil, August, Lawson s.n.

(BOL!); Wilman s.n. in NBG 3784!14\ locus ignotus, June 1915,

(BOL!).

M. vermeuleniae L. Bol.: 123 (1922). R. wilmaniae (L. Bol.) L.

Bol. var. vermeuleniae (L, Bol.) L. Bol.: 158 (1928-1935; pub-

lished 1929); Jacobsen: 566 (1974). Type: Cape, Niekerkshoop,

April 1921, Wilman s.n. in BOL 15194 (BOL!).

R. wilmaniae (L. Bol.) L. Bol. var. angustifolia L. Bol.: 260

(1936-1958; published 1954); Jacobsen: 566 (1974). Type: Trans-

vaal, Makwassie, April 1954, L.C.C. Liebenberg s.n. in SUG

13156 (BOL!).

Dwarf clump-forming succulents with strongly en-

larged, caudiciform rootstocks and internodes com-

pletely hidden by leaf bases. Leaves glaucous-green,

triquetrous to semiterete, 9-39 (-60) x 2-5 (-7,5)

mm, narrowing towards apices, these often reddish.

Pedicels ± 10 x 1,7 mm, with a pair of leaf-like

bracts, these up to 13,5 mm long and 4 mm thick.

Flowers ± 30 mm in diameter when open. Sepals 5,

outer pair up to 10 x 5 mm, inner 3 up to 8 x 4 mm.

Petals pink to white, 30-50 in 1-2 series, 10-17,5 x

up to 3 mm. Staminodes few to many, sharply dis-

tinct from petals, 3-8 mm long, white with pink

apices. Stamens many; filaments 2-5 (-6,5) mm

long. Stigmas subulate, (2-) 3^1 mm long, roughly

equalling stamens. Capsule turbinate, grey, 6,5 x

8,5 mm; covering membranes covering most of in-

terior; valve wings present, wing-like; placental tu-

bercles small, radial diameter ± 0,4 mm; expanding

keels slightly to widely diverging, fringed. Seeds yel-

lowish brown to maroon, 0,60-1,01 x 0,44-0,76 x

0,39-0,72 mm, micropylar region 0,20-0,37 mm

long; baculae distinct, raised, but more so on the

micropylar region; microbaculae small to moderate

in size.

Voucher specimens:

CAPE. — 2722 (Olifantshoek): Langkloof (-DC), Leistner

2101 (PRE). 2723 (Kuruman): Kuruman (-AD), Minnaar s.n. in

BOL 24266 (BOL); Barkhuizen 69 (PRE); 6 miles north-east of

Kuruman (-AD); H. Hall s.n. in NBG 139b/56 (BOL). 2724

(Taung): Geluk (-AB), H. Hall s.n. in NBG 139156 (BOL).

E. wilmaniae is the easternmost member of the

genus, and is hardly known west of Prieska. Its near-

est neighbour is E. fulleri , which is not found east of

Keimoes, about 150 km west of the westernmost re-

cord of the present species. The range of E. wilma-

niae extends eastwards as far as Makwassie in the

Transvaal, northwards as far as Kuruman and south-

wards as far as Niekerkshoop, near Prieska (see Fig-

ure 10).

The leaves of this species may be sharply trique-

trous to semiterete. Triquetrous-leaved forms ap-

proach E. montis-moltkei in general appearance, but

differ from that species in having larger, paler-

coloured flowers with distinct bracts, and in having

larger capsules. Semiterete-leaved forms approach

£. Candida in appearance. That species, however,

has ternate flowers and leaves laterally compressed

so that they are thicker than wide.

3.2 Ebracteola fulleri (L. Bol.) Glen , comb.

nov.

Ruschia fulleri L. Bol.: 159 (1928-1935; published 1929); Jacob-

sen: 552 (1974). Type: Cape, Pella, August 1929, Fuller 48

(BOL!).

Dwarf clump-forming succulents with strongly en-

larged, caudiciform rootstocks and internodes com-

pletely hidden by leaf bases. Leaves glaucous green,

semiterete to terete, (13-) 15-28 mm long, 2-4 mm

in diameter, narrowing towards apices, these often

reddish. Pedicels ± 12 mm long and 1 mm in di-

ameter, with a pair of small bracts, these up to 4,5

mm long and 1 mm thick, otherwise similar to

leaves. Flowers 25-30 mm in diameter when open.

Sepals 5, outer pair up to 7 mm long and 3,5 mm

wide at base, inner 3 up to 6 mm long and 4 mm wide

at base. Petals pink to white, ± 40 in 1-2 series,

12-18 mm long and up to 2 mm wide. Staminodes

few, sharply distinct from petals, 3,5-6 mm long,

white with pink apices. Stamens ± 30; filaments 1-4

mm long. Stigmas subulate, 3,5-4 mm long, slightly

longer than stamens. Capsule turbinate, grey, 5,5 x

7 mm; covering membranes covering almost all of

interior; valve wings absent; placental tubercles

small, radial diameter ± 0,8 mm; expanding keels

slightly diverging, conspicuously fringed. Seeds whit-

ish, 0,69-0,82 x 0,52-0,63 x 0,41-0,53 mm, micro-

pylar region (0,23-) 0,25-0,33 mm long; baculae dis-

tinct, almost flat; microbaculae small.

Voucher specimens:

SWA/NAMIBIA. — 2616(Aus): Aus (-CB), Erni235 (BOL).

CAPE. — 2817 (Vioolsdrift): Vioolsdrift (-DC), Pillans 6603

(BOL). 2819 (Ariamsvlei): Pella (-CC), Fuller 48 (BOL). 2820

(Kakamas): Kakamas (-DC), Fuller 24 (K). 2919 (Pofadder):

Pofadder (-AB), G. van Zijl s.n. (BOL).

Ebracteola fulleri is widely distributed in the lower

Orange River Valley and along the edge of the Na-

Bothalia 16,2 (1986)

223

mib Desert. Its distribution range extends from Aus

through Vioolsdrift to Kakamas (see Figure 12).

The leaves of this species are semiterete to terete,

distinguishing it from E. montis-moltkei and some

forms of E. wilmaniae. The presence of small bracts

distinguishes the present species from E. derenber-

giana , in which bracts are absent, and from E. Can-

dida and semiterete-leaved forms of E. wilmaniae ,

both of which species have large, almost leaf-like

bracts. Its distribution range also distinguishes this

species from all other members of the genus.

3.3 Ebracteola Candida L. Bol. in Journal of

South African Botany 27: 50 (1961a); Friedrich: 45

(1970); Jacobsen: 472 (1974). Type: SWA/Namibia,

60 miles south of Aus, March 1960, H. Hall

2006= NBG 308/60 (BOL!).

E. vallis-pacis Dinter: 114 (1935), nom. nud.; Dinter ex Range:

255 (1938), nom. nud.

Dwarf clump-forming succulents with enlarged,

caudiciform rootstocks and internodes completely

hidden by leaves. Leaves glaucous-green, semiterete

to obscurely triquetrous, 33-42 (—47,5) mm long, 4-6

(-7) mm wide and 5-8 (-9) mm thick. Flowers often

ternate, otherwise solitary. Pedicels ± 12,5 x 1,5

mm, with a pair of leaf-like bracts up to 22,5 mm

long and 4 mm thick. Flowers ± 25 mm in diameter

when open. Sepals 5, outer pair up to 10 x 5 mm,

inner 3 up to 8 x 4 mm. Petals white, ± 50, 12-19 x

up to 2 mm. Staminodes many, white, 3,5-7 mm

long. Stamens many; filaments 2-5,5 mm long. Stig-

mas subulate, 3-4,5 mm long, roughly equal in

length to stamens. Capsule not seen. Seeds whitish,

0,80-0,97 x 0,63-0,71 x 0,55-0,67 mm, micropylar

region 0,31-0,41 mm long; baculae low but distinct;

microbaculae small to moderate in size.

Voucher specimens:

SWA/NAMIBIA. — 2615 (Luderitz): Halenberg (-CB),

Merxmuller & Giess 3464 (M). 2616 (Aus): !Aus (-CB), Schinz

2059 ( Z ). 2716 (Witputz): 60 miles south of Aus (-BC), H. Hall

2006 = NBG 308160 (BOL).

Plants of this species with ternate flowers are dis-

tinguished from all other species in the genus by this

character. The presence of bracts on the pedicel dis-

tinguishes this species from E. derenbergiana and E.

montis-moltkei ; the much greater size of the bracts

distinguishes this species from E. fulleri. The rela-

tively broader, slightly laterally compressed leaves

and the distribution range (Figure 28) distinguish E.

Candida from E. wilmaniae.

3.4 Ebracteola derenbergiana ( Dinter ) Dinter &

Schwant. in Zeitschrift fur Sukkulentenkunde 3: 24

(1927); Friedrich: 46 (1970).

Mesembryanthemum derenbergianum Dinter: 137 (1927). Berg-

eranthus derenbergianus (Dinter) Schwant.: 180 (1926). Ruschia

derenbergiana (Dinter) L. Bol. in Jacobsen 3: 1631 (1955), nom.

invalid. R. derenbergiana (Dinter) C. Weber: 11 (1968); Jacob-

sen: 550 (1974). Lectotype: SWA/Namibia, Jakkalskuppe, 1

November 1922, Dinter 3645 (B, holo.l; SAM, iso.!).

M. derenbergianum Dinter var. interioris Dinter: 105 (1928),

nom. nud.

Dwarf clump-forming succulents with strongly en-

larged, caudiciform rootstocks and internodes com-

pletely hidden by leaf bases. Leaves glaucous green,

semiterete to terete, 10-39 (-48) x 2,5-7 mm, nar-

FIGURE 28. — Distribution of Ebracteola Candida, A ; and E.

derenbergiana, O.

rowing towards apices, these often reddish. Pedicels

± 10 x 2 mm, without bracts. Flowers ± 20 mm in

diameter when open. Sepals 5, outer pair up to 9,5 x

4,5 mm, inner 3 up to 7,5 x 4 mm. Petals magenta,

50-60 in 1-2 series, 10-15 x up to 1,5 mm. Stami-

nodes present, sharply distinct from petals, (4-) 5-7

mm long, white with pink apices. Stamens many;

filaments 2, 5-5,5 mm long. Stigmas subulate, 2-3

mm long, shorter than stamens. Capsule turbinate,

grey, 6x8 mm; covering membranes covering most

of interior; valve wings present, awn-like; placental

tubercles large, radial diameter ± 1,2 mm; expand-

ing keels slightly diverging, unadorned. Seeds yel-

lowish brown, 0,60-0,89 x 0,48-0,68 x 0,33 - 0,53

mm, micropylar region (0,17-) 0,21-0,31 mm long;

baculae distinct, almost flat; microbaculae small.

Voucher specimens:

SWA/NAMIBIA. — 2516 (Helmeringhausen): Helmeringhau-

sen (-DC), Merxmuller & Giess 3453 (M). 2615 (Luderitz): Ha-

lenberg (-CB), Dinter 2638 (B, SAM). 2616 (Aus): Plateau (-CB)

H. Hall s.n. in NBG 140160 (BOL). 2716 (Witputz): Pockenbank

(-BA), Dinter 6221 (B, SAM). 2816 (Oranjemund): Scha-

kalsberge (-BA), Giess 9115 (WIND).

Friedrich (1970) cites only one of the Dinter speci-

mens in full, merely noting that four other specimens

from different localities were cited in the proto-

logue. This may be regarded as being equivalent to

the choice of a lectotype, and to the extent that it is,

the choice is followed here. The Berlin sheet is cited

as holo-lectotype, as it was annotated by Friedrich,

while the SAM sheet was not so annotated.

The semiterete to terete, rather than sharply tri-

quetrous leaves distinguish this species from E. mon-

tis-moltkei. Other useful characters include the much

thicker pedicels, narrower petals of generally deeper

magenta colour, staminodes which do not merge

into petals, and conspicuous placental tubercles in

the capsules. The absence of bracts and different dis-

tribution range (Figure 28) distinguish this species

from E. fulleri and E. wilmaniae. Differences be-

tween E. derenbergiana and E. Candida are dis-

cussed under the latter species.

3.5 Ebracteola montis-moltkei (Dinter) Dinter &

Schwant. in Zeitschrift fur Sukkulentenkunde 3: 24

(1927); Friedrich: 46 (1970); Jacobsen: 472 (1974).

224

Bothalia 16,2 (1986)

Mesembryanthernum montis-moltkei Dinter: 113 (1922). Syn-

types: SWA/Namibia, ostlicher Gipfel der Auasberge, 1899,

Dinter H297 (M, holo-syn.!; SAM, iso-syn.!). SWA/Namibia,

Moltkeblick, no date, Dinter 7565; Moltkeblick und Kempinsky-

berg, 5 May 1922, Dinter 3509 (B, holo-syn.!; SAM. iso-syn.!).

M. renniei L. Bol.: 24 (1927). Ruschia renniei (L. Bol.)

Schwant. ex Jacobsen: 58 (1949). Type: SWA/Namibia, Moltke-

blick, August - September 1925, Rennie s.n. in NBG 728125

(BOL, holo.!; K, iso.!).

Dwarf clump-forming succulents with strongly en-

larged, caudiciform rootstocks and internodes com-

pletely hidden by leaf bases. Leaves glaucous green,

sharply triquetrous, 12^-1 mm long, 2-7 (-9) mm

thick, often somewhat thicker than wide, narrowing

towards apices, these often reddish. Pedicels ± 7,5

x 1,3 mm, without bracts. Flowers 15-30 mm in di-

ameter when open. Sepals 5, the outer pair up to 11

x 5 mm, inner 3 up to 9 x 4 mm. Petals magenta to

white, 25-60 in 1-2 series, (6-) 8-14 x up to 2 mm.

Staminodes many, merging into petals, 2, 5-7, 5 mm

long, white with pink apices. Stamens 35-75; fila-

ments 2-4 (-6) mm long. Stigmas subulate, 2-4 mm

long, shorter or longer than stamens. Capsule turbi-

nate, grey, 5 x ±7 mm; covering membranes cover-

ing most of interior; valve wings present, awn-like to

wing-like; placental tubercles absent or small, radial

diameter ± 0,8 mm; expanding keels slightly to

moderately diverging, fringed. Seeds whitish to ma-

roon, 0,48-0,60 (-0,84) x 0,35-0,47 x 0,45-0,51

(-0,60) mm, micropylar region (0,14-) 0,19- 0,31

mm long; baculae distinct, almost flat; microbaculae

large.

Voucher specimens:

SWA/NAMIBIA. — 2217 (Windhoek): Ruschberg (-CA),

Dinter 2641 (B), Dinter 4375 (HBG); Moltkeblick (-CB), Dinter

3509 (B, SAM); Giess 11511 (WIND). 2317 (Nauchas); Klein

Aub (-DC), Giess 8793 (WIND).

Again, the Dinter specimens cited as holo-syn-

types above are those annotated by Friedrich.

The absence of bracts in this species and widely

separated distribution ranges separate E. montis-

moltkei on the one hand from E. fulleri and E. wil-

maniae on the other. The sharply triquetrous leaves

provide another useful character distinguishing this

species from E. fulleri , while the staminodes merg-

ing into petals serve to distinguish E. montis-moltkei

from E. wilmaniae. Differences between this species

and others of the genus not mentioned above are dis-

cussed under those species. The distribution of this

species is shown in Figure 13.

ACKNOWLEDGEMENTS

The curators of the following herbaria are thanked

for facilities made available to the author as a visitor,

and for the loan of material: B, BOL, G, J, K, M,

NBG, S, SAM, WIND and Z. Part of this work was

done while at Kew as South African Liaison Officer;

the Director and staff of the Royal Botanic Gardens,

Kew are thanked for every kind of assistance and

encouragement, and especially for SEM facilities. I

should like to thank Mr D. S. Hardy, Dr O. A.

Leistner and Mr E. J. van Jaarsveld for helpful com-

ment and suggestions made while this paper was in

draft.

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SPECIMENS EXAMINED

Acocks 8573 (3.1) PRE. Archer 355 (3.4) BOL.

Barkhuizen 69 (3.1) PRE. H. Bolus 11285 (2.1) BOL. H. M. L.

Bolus s.n. in NBG 880/15 (2.1) K; s.n. in NBG 718/33 (2.4) BOL;

s.n. (2.3) BOL; s.n. (2.4) BOL. Broom s.n. in NBG 868/33 (3.1)

BOL, K, PRE; s.n. in NBG 2631/33 (3.1) BOL.

Compton s.n. in NBG 1188/24 (2.4) BOL. Compton & Cook s.n.

in NBG 1992/23 (2.1) BOL.

De Jager s.n. in BOL 24718 (2.3) BOL. De Villiers s.n. in NBG

958/31 (2.4) BOL. Dinter 2638 (3.4) B, SAM; 2641 (3.5) B; 3509

(3.5) B, SAM; 3645 (3.4) B, SAM; 3792 (1.1) B, Z; 4375 (3.5)

HBG; 6621 (3.4) B, SAM; 1/297 (3.5) M, SAM; s.n. (3.5) B, Z;

8186 (1.6) B, K; 8394 (1.5) B; 8395 (1.2) B. Du Plessis 164 (2.2)

BOL; 199 (2.4) BOL; 244 (2.4) BOL; 245 (2.4) BOL; s.n. in NBG

1048132 (2.3) BOL; s.n. (2.4) BOL.

Erni 235 (3.2) BOL. Esterhuysen s.n. in NBG 2818/35 (2.4) BOL;

s.n. (2.4) BOL.

Ferguson s.n. in NBG 1296/27 (2.4) BOL; s.n. in NBG 1297/27

(2.1) BOL; s.n. (2.1) BOL. Frames s.n. in NBG 102/28 (2.4)

BOL; s.n. (2.4) BOL. Fuller 24 (3.2) K; 48 (3.1) BOL.

Giess 8793 (3.5) WIND: 9115 (3.4) WIND; 11511 (3.5) WIND;

12842 (3.4) S, WIND. Giess & Muller 14380 (1.2) M; 14401 (1.2)

M. Giess, Volk & Bleissner 5421 (1.4) WIND.

H. Hall 1308a (1.2) BOL; 1322a (1.2) NBG; 1869 (1.5) BOL;

1869a (1.2) BOL; s.n. in NBG 108/53 (1.2) BOL; s.n. in NBG

489/55 (1.6) BOL; s.n. in NBG 107158 (1.2) BOL; s.n. in NBG

120/58 (1.2) BOL; s.n. in NBG 158/58 (1.2) BOL. Hardy 4636

(1.6) PRE; 4826 (1.4) PRE. Hattingh s.n. in NBG 842/69 (2.1)

NBG. Helm s.n. in NBG 1761/32 (2.1) BOL; Herre s.n. in SUG

9194 (1.2) BOL; s.n. in SUG 9202 (1.2) BOL; s.n. in SUG 9270

(1.2) BOL; s.n. in SUG 10234 (2.1) BOL; s.n. in SUG 11601 (2.1)

BOL; s.n. in SUG 11608 (2.3) BOL; s.n. in SUG 12118 (2.4)

BOL; s.n. in SUG 13063 (2.4) BOL; s.n. in SUG 13065 (2.1)

BOL; s.n. in SUG 13066 (2.4) BOL; s.n. in SUG 13067 (2.4)

BOL; s.n. in SUG 14693 (1.3) BOL. Hill s.n. in BOL 27253 (1.1)

BOL. Holloway 1 (1.1) BOL; 17 (1.1) BOL; 24 (1.6) BOL; 33

(1.1) BOL; 58 (1.4) BOL.

James s.n. (3.1) BOL. Judd s.n. in NBG 923/18 (3.1) BOL.

Lavis s.n. in BOL 21383 (2.4) BOL. Leighton 2532 (1.2) BOL.

Leipoldt s.n. (2.4) BOL. Leistner 2101 (3.1) PRE; 3408 (1.2)

PRE. Lewis s.n. in NBG 142/27 (2.1) NBG. Liebenberg s.n. in

SUG 13156(3.1) BOL. Littlewood s.n. in KG 756/61 (1.6) M; s.n.

in KG 816/61 (1.2) M. J. Luckhoff 7/34 (1.1) BOL.

Marloth 6329 (3.1) PRE. Merxmuller & Giess 2751 (3.4) M; 3453

(3.4) M; 3463 (3.3) M. Middlemost s.n. in NBG 2703/27 (2.3)

BOL. Minnaar s.n. in BOL 24266 (3.1) BOL. Muir 2701 (2.1)

BOL, K; s.n. (2.1) K.

Pillans 5725 (1.1) BOL; 5830 (1.2) BOL; 6603 (3.1) BOL.

Rennie s.n. in NBG 728/25 (3.5) BOL, K. Rusch sub Dinter 8394

(1.5) B. Rusch & Erni sub Holloway 17 (1.1) BOL; 24 (1.6) BOL;

33 (1.1) BOL; 58 (1.4) BOL.

Salter 4140 (2.4) BOL. Schenck 226 pro parte (1.2) Z. Schinz 2059

(3.3) Z. Smith s.n. (2.4) BOL.

P. A. B. van Breda 1694/60 (1.2) BOL. Van der Bijl 33 (2.1) K. P.

van Heerde s.n. in NBG 251/62 (1.7) BOL. Van Zijl s.n. (3.2)

BOL.

Werger 444 (1.2) PRE. Wilman s.n. in BOL 15194 (3.1) BOL.

Wisura 626 (1.2) NBG; 677 (1.2) NBG; 1359 (2.1) NBG; 1481

(1.2) NBG; 1500 (1.2) NBG; 1522 (1.2) NBG; 1539 (1.2) NBG;

1579 (1.3) NBG; 1588 (1.1) NBG.

INDEX

Acrodon N. E. Br., 212

bellidiflorus (L.) N. E. Br., 214

duplessiae (L. Bol.) Glen, 217

leptophyllus (L. Bol.) Glen, 217

parvifolius R. du Plessis, 216

subulatus (Mill.) N. E. Br., 214

Astridia Dinter, 205

alba (L. Bol.) L. Bol., 209

blanda L. Bol., 207

forma angustata L. Bol., 207

forma latipetala L. Bol., 207

citrina (L. Bol.) L. Bol., 210

226

Bothalia 16,2 (1986)

dinteri L. Bol.

var. lutata L. Bol. ex Jacobsen, 207

dulcis L. Bol. , 209

hallii L. Bol., 211

herrei L. Bol., 210

hillii L. Bol., 208

latisepala L. Bol., 209

longifolia (L. Bol.) L. Bol., 209

maxima (Haw.) Schwant., 212

rubra (L. Bol.) L. Bol., 209

var. alba L. Bol., 209

var. citrina L. Bol., 210

ruschii L. Bol., 211

speciosa L. Bol., 211

swartpoortensis L. Bol., 209

vanbredai L. Bol., 209

vanheerdei L. Bol., 212

velutina Dinter & Schwant., 207

var. lutata L. Bol., 207

Bergeranthus derenbergianus (Dinter) Schwant., 223

Ebracteola Dinter & Schwant., 218

Candida L. Bol., 223

derenbergiana (Dinter) Dinter & Schwant., 223

fulleri (L. Bol.) Glen, 222

montis-moltkei (Dinter) Dinter & Schwant., 223

vallis-pacis Dinter, 223

wilmaniae (L. Bol.) Glen, 222

Lampranthus ruber (L. Bol.) L. Bol., 209

Mesembryanthemum

bellidiflorum L., 214

var. glaucescens Haw., 214

var. simplex DC., 214

var. subulatum (Mill.) Haw., 214

var. viride Haw., 214

derenbergianum Dinter, 223

var. interioris Dinter, 223

longifolium L. Bol., 209

montis-moltkei Dinter, 224

renniei L. Bol., 224

rubrum L. Bol., 209

subulatum Mill., 214

velutinum Dinter, 207

vermeuleniae L. Bol., 222

wilmaniae L. Bol., 222

Ruschia

constricta L. Bol., 217

derenbergiana (Dinter) L. Bol.

nom. invalid., 223

derenbergiana (Dinter) C. Weber, 223

duplessiae L. Bol., 217

fulleri L. Bol., 222

leptophylla L. Bol., 217

longifolia L. Bol., 214

longifolia (L. Bol.) L. Bol., 209

macrophylla L. Bol., 217

renniei (L. Bol.) Schwant. ex Jacobsen, 224

rubra (L. Bol.) L. Bol., 209

wilmaniae (L. Bol.) L. Bol., 222

var. angustifolia L. Bol., 222

var. vermeuleniae (L. Bol.) L. Bol., 222

Bothalia 16,2: 227-233 (1986)

Notes on African plants

VARIOUS AUTHORS

ASCLEPIADACEAE

THE NOMENCLATURE OF SEVERAL BRACHYSTELMA SPECIES FROM SOUTHERN AFRICA

In the course of revisionary studies of the Austra-

lian Asclepiadaceae, with particular reference to

Microstemma R. Br., it became evident that a prob-

lem of priority existed with relation to the con-

generic and predominantly African genus

Brachystelma Sims (non R. Brown, see Forster

1985). The nomenclatural problems involved have

been outlined elsewhere (Forster 1985) and if ac-

cepted, conservation of Brachystelma will avoid the

recombination of some 100 or more names into

Microstemma.

The protologue for Brachystelma (as recognized

by Dyer 1976, 1980) includes two different elements,

namely the illustration of Stapelia tuberosa Meer-

burg: t. 54 fig. 1 (1789) (Figure 1), listed in syno-

nymy of Brachystelma tuberosa R. Br. ex Sims

(1822: t. 2343) and the illustration accompanying the

generic description. Sims in describing Brachystelma

evidently considered the plants depicted in the two

illustrations to be conspecific and his listing in syno-

nymy of S. tuberosa Meerburg makes his name B.

tuberosa R. Br. ex Sims a new combination. Dyer

(1976, 1980, 1983) chooses to regard B. tuberosum

as a new species based on the illustration in Curtis’

Botanical Magazine and excludes S. tuberosa Meer-

burg from synonymy, which is contrary to Art .55.2.

Dyer (1976, 1980, 1983) lists S. tuberosa Meerburg

in the synonymy of Brachystelma caudatum

(Thunb.) N.E. Br., therefore, due to priority, the

name Brachystelma tuberosum R. Br. ex Sims must

be used for this species. This effectively leaves B.

tuberosum sensu Dyer, without a name, as no later

synonyms exist (Dyer, 1976, 1980, 1983). There

would seem to be little difference between B. deci-

piens N.E. Br. and B. tuberosum sensu Dyer, with

the two taxa distinguished by the absence of cilia on

the corolla lobes, a glabrous corolla tube and slightly

more slender corolla lobes in B. decipiens (Dyer

1983). Few collections have been made of either

taxon and their distributions as mapped by Dyer

(1983) are not greatly disjunct. Further collections

may well prove that variation between these taxa is

continuous. Dyer (1983: 34) stated 'Brachystelma

decipiens was so similar to B. tuberosum that N.E.

Br. thought he was being deceived and gave it that

name in consequence. Even now one wonders

whether it should rather be regarded as a subspecies

of B. tuberosum’ .

The degree of ciliation in Asclepiadaceae floral

structures has often been found to be quite variable

on examination of many populations and individuals

(cf. Stapelia , Plowes 1976) and may change on indi-

viduals grown under different environmental condi-

tions (cf. Ceropegia, Field & Collenette 1984).

Examination of herbarium and live material of

Brachystelma microstemma Schltr. (syn. Micro-

stemma tuberosum R. Br.) from Australasia demon-

strated collections with or without cilia on the co-

rolla lobes and with variability in corolla lobe length

(Forster unpublished). The Australasian collections

were in many instances more disjunct than the Afri-

can material being considered.

Despite the apparent restricted endemism of

many southern African Asclepiadaceae, there is

little basis on which to recognize two distinct species

or even subspecies for the populations recognized by

Dyer as B. decipiens and B. tuberosum.

As the two publications by Dyer (1980, 1983) are

likely to remain as the only treatments of the genus

FIGURE 1. — Stapelia tuberosa Meerburg in Plantae rariores vi-

vis coloribus depictae t.54 fig. 1 (1789), here selected as

lectotype.

228

Bothalia 16.2 (1986)

in southern Africa for the foreseeable future, these

nomenclatural changes need to be clearly outlined.

The relevant synonymy is given below. Details of

types are from Dyer (1980, 1983).

Brachystelma tuberosum (Meerburg) R. Br. ex

Sims, in Curtis’ Botanical Magazine 49: t. 2343

(1822), (not the plant depicted).

Stapelia tuberosa Meerburg: t. 54 fig. 1 (1789). Lectotype, selec-

ted here.

Stapelia caudata Thunb.: 46 (1794). Brachystelma caudatum

(Thunb.) N.E. Br.: 169 (1878); R. A. Dyer: 54 (1976); R. A.

Dyer: 8 (1980); R. A. Dyer: 24 (1983). Type: Cape. Thunberg

s.n. Herb. No. 6326 (UPS. holo.: PRE. photo).

Brachystelma spatulatum Lindl. : t. 1113 (1827). Iconotype: Bo-

tanical Register t. 1113 (1827).

Brachystelma crispum Grah.: 170 (1830); N.E. Br.: 839 (1908).

Type: no precise locality, Bowie (no collector indicated) (E-GL,

holo.).

Brachystelma decipiens N.E. Br. in Flora ca-

pensis 4,1: 842 (1908). Type: Cape, near Grahams-

town, Bolton s.n. (K, holo.).

Brachystelma tuberosum sensu R. A. Dyer in Bothalia 12: 54

(1976); R. A. Dyer: 11 (1980); R. A. Dyer: 32 (1983).

REFERENCES

BROWN, N. E. 1878. The Stapelieae of Thunberg's herbarium,

with descriptions of four new genera of Stapelieae. Journal

of the Linnean Society, Botany 17: 162-172.

BROWN, N. E. 1907. Asclepiadeae. In W. T. Thiselton-Dyer,

Flora capensis 4,1: 518-1036. Lovell Reeve, London.

DYER, R. A. 1976. New species of Brachystelma (Asclepiada-

ceae). Bothalia 12: 53-64.

DYER, R. A. 1980. Asclepiadaceae. In O. A. Leistner, Flora of

southern Africa 27,4. Government Printer, Pretoria.

DYER, R. A. 1983. Ceropegia. Brachystelma and Riocreuxia in

southern Africa. Balkema, Rotterdam.

FIELD. D. V. & COLLENETTE. I. S. 1984. Ceropegia superba

(Asclepiadaceae), a new species from Arabia. Kew Bul-

letin 39: 639-642.

FORSTER, P. I. 1985. (790) Proposal to conserve 6870

Brachystelma against Microstemma (Asclepiadaceae).

Taxon 34: 318-319.

GRAHAM, R. A. 1830. In Edinburgh Philosophical Journal 2:

170.

LINDLEY, J. 1827. Brachystelma spatulatum. Spatulate-leaved

Brachystelma. The Botanical Register 13: 1. 1 1 13.

MEERBURG, N. 1789. Plantae rariores vivis coloribus depictae,

t. 54 fig.l. Lugduni Batavorum.

PLOWES, D. C. H. 1976. Problems in Stapelia taxonomy. Aloe

14: 59-64.

SIMS, J. 1822. Brachystelma tuberosa. Tuberous-rooted

Brachystelma. Curtis' Botanical Magazine, ser. 1, 49: t.

2343.

THUNBERG, C. P. 1794. Prodromus plantation 1: 46. Uppsala.

P. I. FORSTER4

* Botany Department. University of Queensland. St Lucia, 4067,

Queensland, Australia.

ASTERACEAE

A NEW RECORD FOR NATAL AND THE SOUTHERN AFRICAN FLORA REGION

The following species, collected by the author in

December 1985, is apparently a new record for Natal

and the southern African flora region:

Chrysocoma mozambicensis Bayer in Mittei-

lungen aus der Botanischen Staatssammlung,

Miinchen 17: 309 (1981). Type: Mozambique, Lou-

rengo Marques [Maputo] Balsinhas 532 (PRE,

holo.).

NATAL. — 2732: Muzi Swamp area (-BA), about 2 km from

Phelendaba turnoff on Mbazwana road. Forest clump in loose

sandy soil. Shrublet with yellow florets. 3.12.1985. G. Germishui-

zen 3571 (PRE).

This species has its main distribution in Mozambi-

que.

G. GERMISHUIZEN

EBENACEAE

A NEW SPECIES OF EUCLEA FROM THE TRANSVAAL

Euclea dewinteri Retief, sp. nov., E. crispae

(Thunb.) Guerke affinis, sed marginibus laminarum

foliorum non undulatis, lamina ovata vel elliptica

non obovata vel lanceolata atque pedunculis inflo-

rescentiae valde brevioribus differt.

TYPE. — Transvaal, 2430 (Pilgrim’s Rest):

path from Bourke’s Luck passing the old mine down

to Belvedere (-DB), Davidson 3628 (PRE, holo.;

J).

A virgate,single-tomulti-stemmedshrublet, 1-2 m

high, branched at the ends of the stems. Branches

hairy when young, glabrescent when older. Leaves

simple, spirally arranged; crowded at the ends of the

branches; blade broadly ovate to elliptic, 5-26 x

3-15 mm, densely hairy when young, glabrescent

when older, apex obtuse to rounded, base rounded.

margin entire; petioles more or less appressed,

1-3 mm long, densely hairy when young, glabrescent

when older. Inflorescence with both male and female

flowers single or in 3-flowered pseudocymes. Flow-

ers dioecious. Male flowers greenish yellow to dull

white; calyx saucer-shaped, densely hairy, 4-lobed,

deltoid; corolla campanulate, cleft at least halfway

down or more, appressed trichomes present along

the middle, 2,5-3 mm long; stamens with filaments

0,75 mm long; ovary rudimentary, usually with two

slender styles, densely hairy, disc present. Female

flowers smaller than male flowers; corolla subcam-

panulate, 2-2,5 mm long; staminodia present. Fruit

a globose berry with a persistent non-accrescent ca-

lyx, purplish black when ripe, hairy when young,

5,5-7 mm in diameter, one-seeded; seed globose,

4-6 mm in diameter, divided into three parts by two

thin curved lines and a shallow groove. Figure 2.

Bothalia 16,2 (1986)

229

FIGURE 2. — Euclea dewinteri

E. Retief. Branch, x 0,6.

(from Davidson 3628).

TRANSVAAL. — 2430 (Pilgrim’s Rest): Blyderivierspoort

Nature Reserve, Bourke’s Luck Potholes. ± NE of parking area.

May 1970, Scheepers & Engelbrecht 1256 (PRE); on quartzite

ridges, September 1970, Kerfoot 6444 (PRE); Belvedere Valley,

quartzite outcrops, September 1970, Kerfoot 6445 (PRE); at junc-

tion of Blyde and Treur Rivers, February 1973. White 10261

(PRE); below old mine. August 1978. Birchmore 1126 (PRE);

trail above old mine. November 1978. Kruger 312 (PRE); path

from Bourke's Luck passing the old mine down to Belvedere,

April 1982. Davidson 3628 (J, PRE).

E. dewinteri is endemic to the Transvaal, being re-

stricted to the Blyderivierspoort Nature Reserve

where it grows against quartzite hillslopes, often

rooted in crevices between boulders. The species is

often found in association with species of Smilax,

Bowkeria, Rhus, Bequaertiodendron, Helichrysum,

Phylica, Syzygium, Cliffortia and Halleria. It also

occurs in Loudetia-Monocymbium Grassland of the

North Eastern Mountain Sourveld. E. dewinteri

flowers and fruits from September till May.

In southern Africa species of the genus Euclea can

be divided into two groups based on corolla struc-

ture. In the one group the corolla is shallowly lobed

at the apex only (seven species), while in E. dewin-

teri, together with eight other species, the corolla is

cleft at least halfway down or more. Five of the

species in this latter group have young leaves and

twigs that are quite glabrous or covered with a rust-

coloured granular exudate, while in E. dewinteri, E.

asperrima Holzh., E. crispa (Thunb.) Guerke and E.

natalensis A. DC. they are pubescent or asperulous.

E. natalensis usually has a compound inflorescence

and keeled corolla lobes. The inflorescence of E. de-

winteri, E. crispa and E. asperrima is a pseudora-

ceme and the corolla lobes are without a keel. The

corolla of E. asperrima is hairy on the outside, the

young twigs and leaves of the species are scabrid or

asperulous. E. dewinteri and E. crispa are distin-

guished by a corolla that is glabrous except for a

median line of appressed bristles and young twigs

and leaves that are pubescent with fairly long hairs.

E. dewinteri is most closely related to E. crispa,

especially in flower structure. Our species differs

from E. crispa in (i) having the leaf blades ovate to

elliptic and not obovate to lanceolate; (ii) not having

leaf blades with undulate margins; and (iii) having

much shorter peduncles than E. crispa. E. dewinteri

differs from the other known species of the genus in

growth form, being a virgate single- or multi-

stemmed shrublet, 1-2 m high with divaricate

branching at the end of the stems.

The specific epithet dewinteri has been chosen in

recognition of the work on the family Ebenaceae for

the Flora of southern Africa done by Dr. B. de Win-

ter, Director of the Botanical Research Institute,

and of his continued interest in the family.

E. RETIEF

230

FABACEAE

A NEW SPECIES OF INDIGOFERA FROM THE SOUTHERN CAPE

Bothalia 16,2 (1986)

Indigofera thesioides J. K. Jarvie & C. H. Stir-

ton, sp. nov., affinitate incerta.

Suffrutex porrectus vel suberectus usque 0,4 m al-

tus, dense ramosus, cinereus, omnino strigulis ad-

pressis instructus. Stipulae liberae usque 1 mm

longae, anguste triangulares. Folia trifoliolata, lat-

eralia mox caduca; anguste obovata conduplicata,

apice recurvato mucronatoque, basi cuneata. Inflo-

rescentia 10-15-flora. Flores 5 mm longi, rosei,

omnes bractea rigida patenti 0,5 mm longa subtenti.

Calycis tubus quam dentibus brevior. Vexillum late

ovatum dorso striguloso. Alae 4 mm longae. Carinae

4, 0-4,5 mm longae clavula superficie exteriore cen-

traliter disposita deorsum aspicienti. Antherae apicu-

latae squamis carentibus. Pistillum brevipedicella-

tum, ad apicem basinque compressum lateribusque

rotundatis. Fructus ferruginobrunnei pilis albis ad-

pressis obtecti. Figure 3.

TYPE. — Cape, 3322, (Oudtshoorn): Meiring’s

Poort (-BC), 20.6.1965, Acocks 18288 (K, holo.!;

PRE, iso.!).

Sprawling to semi-erect shrublet up to 0,4 m tall,

densely twiggy, branching off from the basal stock;

greyish, appressed strigulose all over. Stipules free,

up to 1 mm long, narrowly triangular. Leaves trifo-

liolate, laterals rapidly caducous; 4—5 x 0,5-1 ,0 mm,

narrowly obovate, apex recurved mucronate, base

cuneate, conduplicate, densely appressed strigulose

on both surfaces. Petiole 1 mm long; petiolules very

short. Inflorescence 25-35 mm long, 10-15-flowered;

peduncle 7-8 mm long. Flowers 5 mm long, pink,

each subtended by a stiff, patent, 0,5 mm long, cadu-

FIGURE 3. — Holotype of Indigofera thesioides, Acocks 18288.

FIGURE 4. — Indigofera thesioides. 1, flower, x 6; 2, calyx opened out, x 10; 3, standard, x 12; 4, keel petal, x 12; 5, wing petal,

x 12; 6, pistil, x 12; 7, apex of the stamina) sheath, x 30; 8, fruit, x 7.

Bothalia 16,2 (1986)

231

cous bract; pedicel < 1 mm long. Calyx 3, 0-3, 5 mm

long; tube shorter than the teeth; keel tooth 0,5 mm

longer than the rest, narrowly triangular, densely

covered in appressed biramous hairs. Standard 5 x

3,5 mm, broadly ovate, back of standard strigulose,

claw short, auricles scarcely developed, apex some-

what mucronate; appendages absent. Wing petals 4

x 2 mm, ± length of the keel blades, auriculate.

Keel blades 4, 0-4,5 x 2, 0-2,5 mm, peg situated cen-

trally on the outer surface and pointing downwards.

Androecium 4 mm long, vexillar stamen free; an-

thers uniform, <0,5 mm wide, apiculate, anthers on

long thin filaments basifixed, anthers on short thick-

ened filaments dorsifixed; scales absent. Pistil 4 mm

long; ovary 3 mm long, shortly stalked, flattened on

top and bottom, sides rounded, narrowly oblong;

style upcurved, height of curvature 1,5 mm; stigma

capitate. Fruit 10-15 x 2 mm, reddish brown and

covered in white appressed hairs. Seeds unknown.

Figure 4.

This rare species is found in the upper margins of

Spekboomveld on steep rocky slopes and in tran-

sitional fynbos. It occurs at about 700 m altitude.

Flowering takes place in June.

CAPE. — 3322 (Oudtshoorn): Meiring’s Poort (-BC),

20.6.1965, Acocks 18288 (K, PRE); 4,2 miles WNW of Camfer

Station (-CD), 22.12.1962, Acocks 23256 (K, PRE).

J. K. JARVIE and C. H. STIRTON

A NEW RECORD FOR NATAL

Tephrosia lupinifolia (Burch.) DC., Prodromus

systematis naturalis regni vegetabilis 2: 255 (1825).

Type: Cape Province, Little Klobbokhonni near

Harnapery, Bure hell 2488 (K,G).

NATAL. — 2732 (Ubombo): Muzi Swamp area (-BA), about

2 km from Phelendaba turnoff on Mbazwana road, in grassland in

depression. Trailing herb with 5 leaflets on a long petiole. Flowers

pink. 26.3.1985. G. Germishuizen 3119 (PRE).

There appears to be no previous record of this

species occurring in Natal. The main distribution of

T. lupinifolia is in South West Africa/Namibia, Bo-

tswana, the central and western Transvaal, Orange

Free State and northern Cape Province.

G. GERMISHUIZEN

LILIACEAE

NOTES ON KNIPHOFIA

Kniphofia ichopensis Schinz var. aciformis

Codd, var. nov., a typo speciei foliis acicularibus dif-

fert.

TYPE. — Natal, Kamberg, F. B. Wright 2 (PRE,

holo.; NU, iso.). Figure 5.

In var. aciformis the leaves differ conspicuously

from normal K. schinzii in being acicular, up to 200

mm long and 0,5-1 mm in diameter, and in being

produced in dense tufts of 20-30 leaves from which

one or two peduncles may be produced. The leaves

are surrounded at the base by numerous fibrous leaf-

bases persisting from previous seasons. The leaf

margins are inrolled and are minutely denticulate. In

the typical variety the leaves are about 6-8 per pe-

duncle, flat with a distinct keel and soft in texture,

500-800 mm long and 5-10 mm broad.

The perianth and bract characters of var. acifor-

mis and var. ichopensis are almost identical and for

this reason the new entity is placed as a variety of K.

ichopensis. The leaves of var. aciformis are, how-

ever, quite unlike any other member of the genus

and further investigation may indicate that it is

worthy of separate specific status. At present it is

known from only the three gatherings listed below,

all of which fall within the distribution range of typ-

ical K. ichopensis. No specimens with leaves inter-

mediate in character between var. aciformis and var.

ichopensis have been seen.

NATAL. — 2929 (Underberg): Kamberg area (-BC), flow-

ering 14.11.1959, F. B. Wright 2 ( PRE); flowering 28.11.1974, F.

B. Wright 1961 (NU); Mahwaqa (Marwaga) Mtn, near Bulwer

(-DC), flowering 28.12.1980, M. A. Rennie 1193 (NU).

Kniphofia angustifolia (Bak.) Codd , stat. nov.

K. natalensis Bak. var. angustifolia Bak. in FI. Cap. 6: 281

(1896). Type: Natal, Tabamhlope Mtn, Evans 411 (K. holo.; NH,

PRE). Figure 6.

K. rufa sensu Codd in Bothalia 9: 434 (1969).

In my revision of the South African species in Bo-

thalia 9: 434 (1969), the name K. rufa Bak. was

adopted with some hesitation for a group of speci-

mens from the Natal midlands and foothills of the

Drakensberg with slender, lax inflorescences (per-

ianth 20-30 mm long) and narrow, grass-like leaves,

2-5 mm broad.

At the time it was pointed out that the type of K.

rufa in Herb. Kew was possibly of hybrid origin and

was not matched exactly by any specimens collected

in the wild state. The inflorescence is denser than in

the wild plants and the leaves are 8 mm broad. The

orginal plant was grown by Max Leichtlin in his nur-

sery at Baden-Baden and forwarded to Kew in June

1899. It was figured and described in Curtis's Botan-

ical Magazine t. 7706 (1900). The illustration shows

a medium-lax inflorescence of yellow flowers about

24 mm long, tinged with red in the bud stage. Since

the 1969 revision was published, no specimens have

been collected which are a good match of the type of

K. rufa and it is proposed to place K. rufa as an in-

sufficiently known entity until matching material is

forthcoming from naturally growing plants.

The type of K. angustifolia has a lax inflorescence

with creamy-white flowers about 20 mm long, and

leaves 2-3 mm broad. The present concept of the

232

Bothalia 16,2 (1986)

<X **■*-.

v„. IMP. N.,. <<**% /J1. liJriy/W

*- !+/"/*? -■ 3.

FIGURE 5. — Kniphofia ichopensis var. aciformis , holotype in

PRE.

species includes plants with flowers varying in length

from 19-30 mm and in colour from creamy-white to

yellow or coral-red. There is some association be-

tween perianth colour and length, with the coral-red

flowers tending to be longer than cream or yellow

flowers. It seems possible that the coral-red and

orange-red colour may be derived from hybridiza-

tion with K. triangularis , which has small dense in-

florescences of coral-red to orange-red flowers 24-35

mm long. K. triangularis also occurs in the foothills

of the Natal Drakensberg and apparent hybridiza-

tion between this species and K. fibrosa Bak. has

been noted by recent collectors such as Mrs M. A.

Rennie on Mahwaqa Mtn near Bulwer and by O. M.

Hilliard and B. L. Burtt at Bushman’s Nek.

REFERENCES

BAKER, J. G. 1896. Liliaceae. Flora capensis 6: 281.

BAKER. J. G. 1900. Kniphofia rufa. Curtis' Botanical Magazine.

t. 7706.

CODD. L. E. 1969. The South African species of Kniphofia (Li-

liaceae). Bothalia 9: 363-512.

L. E. CODD

POLYGONACEAE

RAISING THE RANK OF POLYGONUM SENEGALENSE FORMA ALBOTOMENTOSUM TO SUBSP.

ALBOTOMENTOSUM

Southern African material of the two forms of

Polygonum senegalen.se Meisn., namely forma sene-

gale nse and forma albotomentosum R. A. Grah., can

be clearly distinguished on the basis of their pubes-

cence: forma senegalense is glabrous or nearly so,

whereas forma albotomentosum. as the epithet im-

plies, has a white tomentum. Tropical African ma-

terial of the two forms represented at PRE, also

shows these differences. The two forms are herewith

regarded as subspecies and their rank is formally

raised:

Bothalia 16,2 (1986)

233

Polygonum senegalense Meisn. subsp. alboto-

mentosum (R. A. Grah.) Germishuizen, stat. nov.

Polygonum senegalense Meisn. forma albotomentosum R. A.

Grah. in Kew Bulletin 1936: 258 (1956); R. A. Grah.: 19 (1958);

Ross: 156 (1972). Type: Tanganyika [Tanzania], Ufipa District,

Lake Kwela, Bullock 2666 (K, holo.!; PRE. photo.!).

REFERENCES

GRAHAM, R. A. 1956. Kew Bulletin 12: 258.

GRAHAM, R. A. 1958. Polygonaceae. Flora of Tropica! East

Africa: 19.

ROSS, J. H. 1972. Flora of Natal. Memoirs of the Botanical Sur-

vey of South Africa No. 39: 156.

BILDERDYKIA AND REYNOUTRIA NEW TO THE FLORA OF THE SOUTHERN AFRICAN REGION

Two genera, represented by species previously

placed under Polygonum , are here recorded for the

first time for the region of the Flora of southern

Africa. They are Bilderdykia Dumort., represented

here by Bilderdykia convolvulus (L.) Dumort. and

Reynoutria Houtt., represented here by Reynoutria

sachalinensis (F. Schmidt) Nakai. These species are

widespread naturalized weeds in our region.

G. GERMISHUIZEN

Bothalia 16,2: 235-241 (1986)

Leaf anatomy of the South African Danthonieae (Poaceae). XIV.

Pentameris dregeana

R. P. ELLIS*

Keywords: Danthonieae, leaf anatomy, Pentameris , Poaceae

ABSTRACT

Transverse sections and abaxial epidermal scrapes of leaf blades of Pentameris dregeana Stapf. both of herbar-

ium specimens and of freshly fixed material, were examined by light microscopy. The anatomical structure was

found to be basically uniform in a representative sample. A few somewhat atypical specimens, however, showed

epidermal similarities with Pentaschistis colorata (Steud.) Stapf. A comparison with other danthonoid grasses re-

vealed some specimens identified as Pentaschistis colorata var. polytricha Stapf which resemble Pentameris dre-

geana very closely in leaf anatomy. A definite gradation in leaf anatomy between Pentameris dregeana and Penta-

schistis colorata appears to exist and, consequently, it is proposed that the affinities of Pentameris dregeana lie with

this group of Pentaschistis species rather than close to any of the other Pentameris species.

UITTREKSEL

Dwarssnee en abaksiale epidermale skrapings van blaarlaminas van Pentameris dregeana Stapf, beide van her-

bariumeksemplare en van vars gefikseerde materiaal, is met behulp van ’n ligmikroskoop ondersoek. Dit is gevind

dat die blaaranatomie in ’n verteenwoordigende monster basies eenvormig was. Nietemin het ’n paar ietwat afwy-

kende eksemplare epidermale ooreenkomste met Pentaschistis colorata (Steud.) Stapf getoon. Sommige eksem-

plare wat as Pentaschistis colorata var. polytricha Stapf benaam is, het ook sterk anatomiese ooreenkomste getoon

met Pentameris dregeana. Daar is skynbaar ‘n duidelike oorgang tussen die blaaranatomie van P. dregeana en die

van Pentaschistis colorata. Om die rede word voorgestel dat die verwantskappe van Pentameris dregeana met

hierdie groep Pentaschistis- spesies le eerder as met enige ander Pentameris-spesies.

INTRODUCTION

Pentameris dregeana Stapf is a densely tufted per-

ennial which is usually not as robust as the other

members of this genus. The leaf blades are tightly

inrolled and wiry, and the old leaves are characteris-

tically curly. Soft, woolly hairs are particularly com-

mon on the leaf sheath but may also occur near the

base of the blade. The inflorescence is a panicle with

rather small spikelets, the glumes being from 12-15

mm long (Chippindall 1955). The spikelets are

therefore smaller than in any of the other species of

Pentameris , where the glumes range from 18—25 mm

long.

Pentameris dregeana is a species of the mountain

fynbos, and is confined to the mountains of the

south-western Cape Province, where it occurs from

the Clanwilliam District in the north-west to Willow-

more in the east. It favours rocky habitats and is of-

ten found in rock crevices or cliff faces. The species

is even found at high altitudes in the alpine zone but

it does not form low, dense cushions with pungent

leaf apices as does P. macrocalycina (Steud.)

Schweick.

Apart from the statement by De Wet (1956) that

both the epidermal and internal anatomy are festu-

coid, no information on the leaf anatomy of P. dre-

geana is available. It is the purpose of this paper to

describe and illustrate the leaf anatomy of P. dre-

geana in detail and to compare its structure with that

of the other species of the genus as well as the other

South African danthonoid grasses. For the anatom-

* Botanical Research Institute, Department of Agriculture and

Water Supply, Private Bag X101, Pretoria 0001.

ical descriptions, the terminology of Ellis (1976,

1979) will be followed and the following abbrevia-

tions will be used:

vb/s - vascular bundle/s

l’vb/s - first order vascular bundle/s

3’vb/s - third order vascular bundle/s

ibs - inner bundle sheath; mestome sheath

obs - outer bundle sheath; parenchyma sheath

ANATOMICAL DESCRIPTION OF PENTAMERIS

DREGEANA

Leaf in transverse section

Outline of lamina: inrolled from both margins;

probably never open and expanded; not permanent-

ly infolded type but margins usually almost meet,

forming an enclosed, hollow cylinder (Figures 1-9).

11, 13, 15 or 17 vbs in blade section. Ribs and fur-

rows: flat-topped, square adaxial ribs present over

all vbs; deep, cleft-like furrows between all vbs (Fig-

ure 6); ribs over l’vbs and 3’vbs of similar shape and

size. No abaxial ribs or furrows although slight undu-

lations may be associated with the vbs (Figures 3 &

4). Median vascular bundle: structurally identical to

lateral l’vbs; recognizable by location only. Vascular

bundle arrangement: 5, 7 or 9 l’vbs in leaf section; 1

3’vb separates successive l’vbs (Figures 1-9), al-

though laterally this pattern may be obscured. No

2’vbs. All vbs located in centre of blade thickness

(Figure 9) or slightly abaxially (Figure 6). Vascular

bundle description: 3’vbs elliptical with well devel-

oped phloem, l’vbs elliptical with phloem adjoining

the ibs; metaxylem vessels narrow, narrower in di-

ameter than the obs cells (Figure 6). Vascular bundle

sheaths: obs elliptical; interrupted both adaxially and

abaxially by bundle sheath extensions intergrading

236

Bothalia 16,2 (1986)

FIGURES 1-9. — Leaf blade anatomy of Pentameris dregeana as seen in transverse section. 1-6, typical form. 1, Ellis 2480, inrolled

outline, x 100; 2, Ellis 2484, inrolled setaceous leaf, x 100; 3, Esterhuysen 27321, x 100; 4, Esterhuysen 21824, strongly

inrolled blade, X 100. 5-6, Ellis 2494: 5, outline, x 100; 6, detail of adaxial ribs and furrows, mesopyll and vascular bundles,

x 250. 7-9, pubescent form. 7, Ellis 2580, inrolled outline, x 100. 8-9, Ellis 2556: 8, setaceous leaf outline, x 100; 9, detail of

leaf margin, X 250.

Bothalia 16,2 (1986)

237

into sclerenchyma girders (Figures 6 & 9). Obs cells

small, rounded, with thin walls and no chloroplasts.

Ibs entire; composed of rounded cells with thicker

inner tangential cell walls. Sclerenchyma : all vbs

with prominent adaxial and abaxial girders; narrow

towards bundles; girders either intergrade with

thick-walled collenchyma of bundle sheath exten-

sions (Figure 6) or sclerenchyma fibres abut on the

ibs abaxially and the obs adaxially (Figure 9). Very

small sclerenchyma cap in margin (Figure 9). Meso-

phyll: homogeneous chlorenchyma consisting of

regular, tightly packed, isodiametric cells, not ra-

diate (Figures 6 & 9); forming U-shaped groups on

sides and bases of furrows. No colourless cells. Ad-

axial epidermis : small, fan-shaped groups of bulli-

form cells occur at the bases of the furrows (Figures

6 & 9). Epidermal cells small, slightly inflated with a

continuous cuticle (Figure 9); prickles present on

edges of ribs. Abaxial epidermis : no bulliform cells;

epidermal cells small, flattened with a thick continu-

ous cuticle (Figures 6 & 9). No epidermal append-

ages.

Abaxial epidermis in surface view

Intercostal long cells : rectangular, length 2x-3x

width (Figures 10-17); side walls parallel; end walls

vertical; anticlinal walls thickened, without pits, with

regular pointed undulations. Arrangement of adja-

cent files forms brickwork pattern. Adjoining long

cells separated by short cells. Intercostal short cells :

cork-silica cell pairs separate virtually all adjacent

long cells. Cork cell crescentic, enfolding round sil-

ica body; narrower than long cells. Stomata : absent

on abaxial surface (Figures 10-17). Papillae : absent.

Prickles : absent. Microhairs: none observed. Macro-

hairs: either absent (Figures 10-13) or common in

intercostal zones only (Figures 14-17); unicellular,

soft, thin-walled and 1-2 mm long; base slightly

swollen, superficially located between several modi-

fied epidermal cells. Not of cushion hair type. Costal

zones: 5-7 files wide. Long cells of similar length to

intercostal long cells but much narrower; each long

cell separated by a silico-suberose couple consisting

of a crescentic cork cell and a round to elliptical sil-

ica cell.

Specimens examined:

CAPE. — 3219 (Wuppertal): Buffelshoek Pass, Koue Bokke-

veld Mts (-CA), Ellis 2494: Skoongesig, Ceres (-CC), Hanekom

1275. 3318 (Cape Town): Porterville (-BB), Esterhuysen 21907.

3319 (Worcester): Schurfteberg, Great Witzenberge (-AB), Ellis

2484: Leeuwfontein Peak, Gydoberg (-AD), Ellis 2480: Taran-

tula Peak, Esterhuysen 21824 ; Bainskloof (-CA), Esterhuysen

26313: Middagkransberg, Franschhoek Pass (-CC), Boucher

2388*, Ellis 686* . 3321 (Ladismith): Toverkop, Swartberg (-AD),

Esterhuysen 26751* . 3322 (Oudtshoorn): Swartberg Pass (-AC),

Ellis 2556*, 2580*. 3323 (Willowmore): Willowmore (-AD),

Acocks 19925: Formosa Peak (-DC), Esterhuysen 27400*.

DISCUSSION AND CONCLUSIONS

The 14 examined specimens of Pentameris dre-

geana were collected at localities throughout the dis-

* Specimens have abaxial macrohairs.

tribution area of the species. Yet their leaf anatomy

is remarkably uniform, and both the leaf in trans-

verse section (Figures 1-9) and the abaxial epidermis

(Figures 10-17) show negligible variation. This is

considered unusual seeing that ecotypical variation

is common in many fynbos species in response to the

diversity of habitats in this ecologically varied re-

gion.

A superficially striking difference, however, is the

presence of conspicuous, long, soft macrohairs on

some of the specimens of P. dregeana studied (Fig-

ures 14-17). Although this appears to be a signifi-

cant difference, it must be remembered that all

specimens of P. dregeana have this type of macro-

hair on the leaf sheath, particularly at the sheath

mouth (Chippindall 1955). These hairs are possibly

also present on the leaf blades of all P. dregeana

specimens but normally confined to those parts of

the blade below the central third which was sampled

in this study. In the pubescent specimens examined,

this type of hair merely extends somewhat higher up

the leaf blade than is normal. In addition, the leaf

transections of these pubescent specimens (Figures

7-9) are identical to those of the typical specimens

(Figures 1-6). No taxonomic significance is there-

fore, attached to the presence or absence of these

hairs, although pubescent leaf blades were found al-

most exclusively in specimens from the eastern parts

of the distribution area of P. dregeana. This may,

however, represent clinal variation.

A less obvious difference is, that on some epider-

mal preparations costal and intercostal zones are not

differentiated (Figures 10-11). On others this zona-

tion is clearly distinguishable by differences in cell

structure and arrangement (Figures 12-17). The in-

tercostal long cells are rectangular with wavy anticli-

nal walls and the cells of a file are all separated by

small, narrow short cells. The long cells of the costal

zones are much narrower and the interspaced silica

bodies are of the same width as the long cells.

Although the leaf anatomy of P. dregeana is con-

sistently uniform and stable, a few specimens identi-

fied as P. dregeana deviate from the typical structure

to varying degrees (Figures 18-24). In transverse

section these atypical specimens display typical P.

dregeana anatomy (Figures 18-20) but the epidermal

structure differs somewhat. The differences are not

discrete, however, and a continuum exists from

those specimens where the costal and intercostal

zones are almost indistinguishable to the situation in

Figure 24 (Ellis 2477) where costal and intercostal

long cells are significantly different. This particular

specimen also differs from all others in that the silica

bodies are dumbbell-shaped and microhairs occur

between the intercostal long cells (Figure 24). In

transverse section this anomalous specimen is indis-

tinguishable from typical P. dregeana specimens

(Figures 18 & 19), and it is of interest to note that it

was collected at the same locality on the Gydoberg

as Ellis 2480 , which has typical P. dregeana anatomy

(Figures 1 & 13).

These atypical specimens, and Ellis 2477 in par-

ticular, seem to indicate a link between Pentameris

dregeana and Pentaschistis colorata (Steud.) Stapf

238

Bothalia 16,2 (1986)

FIGURES 10-17. — Abaxial epidermis of Pentameris dregeana as seen in surface view. 10-13, typical form: 10, Esterhuysen 26313 ,

showing distribution of costal and intercostal zones, x 160; 11, Esterhuysen 27321, without a clear distinction between costal

and intercostal zones, x 160; 12, Ellis 2484, costal and intercostal zones distinguishable, X 160; 13, Ellis 2480, detail of

intercostal long cells and costal files, x 250. 14-17, pubescent form. 14-15, Ellis 2556: 14, numerous long, soft macrohairs, x

100; 15, detail of intercostal macrohairs and their basal cells, X 250. 16, Boucher 2388, macrohairs common, x 160; 17, Ellis

2580, detail of costal zones, intercostal long cells and macrohairs, x 250.

Bothalia 16,2 (1986)

239

(Figures 25-32). This possible relationship is not evi-

dent in leaf transections, because Pentaschistis colo-

rata and its close allies have very characteristic abax-

ial epidermal cells between the bundles alternating

with small, fibrous cells overlying the bundles.

Nevertheless, relationships of P. dregeana appear to

lie with this group of Pentaschistis species rather

than with any of the other Pentameris species. All

these ‘atypical’ P. dregeana specimens should un-

doubtedly be retained in P. dregeana on gross mor-

phological features and have been artificially separ-

ated here only to accentuate the anatomical link be-

tween P. dregeana and Pentaschistis colorata.

The following P. dregeana specimens display aty-

pical leaf anatomy to varying degrees:

CAPE. — 3219 (Wuppertal): Buffelshoek Pass, Koue Bokke-

veld Mts (-CA), Ellis 2495, 2497. 3319 (Worcester): Leeuwfon-

tein Peak, Gydobcrg (-AD), Ellis 2477.

The anatomical gradation of Pentameris dregeana

into the Pentaschistis colorata species complex ap-

pears to be substantiated by the observation that

some specimens identified as Pentaschistis colorata

(Steud.) Stapf var. polytricha Stapf are virtually

identical to P. dregeana in leaf anatomy e.g. Ellis

2347, 2509 (Figures 25-28).

Ellis 2506 (Figures 29-30), collected at the same

locality as Ellis 2509 (Figures 27-28), has a leaf anat-

omy very closely resembling that of a specimen iden-

tified as Pentaschistis aristidoides (Thunb.) Stapf

(Ellis 2488). The anatomy of Ellis 2506 is dissimilar

< ' i '■ n ' . *

FTGIIRFS 1 8—^4 Leaf anatomy of atypical specimens of Pentameris dregeana. 18-20, leaf in transverse section. 18-19, Ellis

FIGU 2477- 18_ inrolled outline x 100; 19 detail of adaxial ribs, mesophyll and vascular bundles, x 250. 20, Ellis 2495, setaceous

inrolled blade, x 100. 21-24, abaxial epidermal anatomy. 21-22. Ellis 2495: 21. note very long soft macroha.rs associated

with margin x 100; 22, clear distinction between costal and intercostal long cells, x 250. 23, Ellis 2497, with distinct costa

and intercostal zones, x 250; 24, Ellis 2477, costal zones with dumbbell shaped silica bodies and very different intercostal

long cells, x 250.

240

Bothalia 16,2 (1986)

FIGURES 25-32. — Leaf anatomy of Pentaschistis colorata var. polytricha for comparison with the anatomy of Pentameris dre-

geana. 25-26, Ellis 2347: 25, transverse section similar to that of P. dregeana, x 160; 26, abaxial epidermis identical to typical

P. dregeana type, x 250. 27-28, Ellis 2509: 27, typical inrolled outline, x 160; 28, epidermis differing somewhat from P.

dregeana type, x 250. 29-30, Ellis 2506: 29, outline of blade showing conspicuous sclerenchyma girders and thick cuticle, x

160; 30, abaxial epidermis without distinction between costal and intercostal zones, x 160. 31-32, Ellis 2546: 31, leaf outline

showing inflated epidermal cells, x 160; 32, entire abaxial epidermis consists of inflated long cells, x 400.

Bothalia 16,2 (1986)

241

to that of both Pentameris dregeana and Pentaschistis

colorata, and this example demonstrates the definite

interface between Pentameris dregeana and the

genus Pentaschistis. It is clear that the affinities of

Pentameris dregeana are closer to some species cur-

rently placed in Pentaschistis than they are to any of

the Pentameris species.

Ellis 2546 (Figures 31-32) is another specimen

identified as Pentaschistis colorata var. polytricha,

but its leaf anatomy differs from that of all other

danthonoid grasses known to the author. Further

collections of this taxon are needed before it can be

positively identified, but indications are that this

specimen represents a new and undescribed species,

possibly belonging to Pentameris. It is mentioned

here because it emphasizes the extreme heterogene-

ity of Pentaschistis colorata var. polytricha , a taxon

which presently accommodates some specimens

matching Pentameris dregeana as well as specimens

which resemble neither P. dregeana nor Pentaschistis

colorata. Pentaschistis colorata var. polytricha is

therefore a heterogeneous entity which appears to

substantiate the anatomical indications found in this

study, namely that Pentameris dregeana grades into

Pentaschistis and shows closer affinities to this genus

than it does to any other Pentameris species.

The following specimens examined during this

study were identified as Pentaschistis colorata var.

polytricha by the staff of the National Herbarium:

CAPE. — 3219 (Wuppertal): Cedarberg Pass, Algeria State

Forest (-AC), Ellis 2506, 2509. 3319 (Worcester): Franschoek

Pass (-CC), Ellis 2347. 3322 (Oudtshoorn): Robinson’s Pass,

Outeniqua Mts (-CC), Ellis 2546.

Pentameris dregeana resembles some of these

specimens linked to Pentaschistis colorata more than

it does the other species of Pentameris such as P.

longiglumis (Nees) Stapf (Ellis 1985a), P. thuarii

Beauv. (Ellis 1985b), P. macrocalycina (Steud.)

Schweick. (Ellis 1985c) and P. obtusifolia (Hochst.)

Schweick. (Ellis 1985c). The anatomical affinities of

P. dregeana are undoubtedly closer to Pentaschistis

colorata and its allies than to the other members of

the genus Pentameris. It’s leaf anatomy appears to

be somewhat intermediate between these two gen-

era and a final decision on the classification of this

interesting species awaits a thorough revision and re-

evaluation of the genus Pentaschistis.

ACKNOWLEDGEMENTS

Miss L. Smook is thanked for identifying the

voucher specimens, Mrs H. Ebertsohn for technical

assistance, Mrs A. Romanowski for the photography

and Mrs M. van der Merwe for typing the manu-

script.

REFERENCES

CHIPPINDALL, L. K. A. 1955. In D. Meredith, The grasses and

pastures of South Africa. Central News Agency, Johannes-

burg.

DE WET, J. M. J. 1956. Leaf anatomy and phylogeny in the tribe

Danthonieae. American Journal of Botany 43: 175-182.

ELLIS, R. P. 1976. A procedure for standardizing comparative

leaf anatomy in the Poaceae. I. The leaf blade as viewed in

transverse section. Bothalia 12: 65-109.

ELLIS, R. P. 1979. A procedure for standardizing comparative

leaf anatomy in the Poaceae. II. The epidermis as seen in

surface view. Bothalia 12: 641-672.

ELLIS, R. P. 1985a. Leaf anatomy of the South African Dantho-

nieae (Poaceae). XI. Pentameris longiglumis and Pentame-

ris sp. nov. Bothalia 15: 567-571.

ELLIS, R. P. 1985b. Leaf anatomy of the South African Dantho-

nieae (Poaceae). XII. Pentameris thuarii. Bothalia 15:

573-578.

ELLIS, R. P. 1985c. Leaf anatomy of the South African Dantho-

nieae (Poaceae). XIII. Pentameris macrocalycina and P.

obtusifolia. Bothalia 15: 579-585.

Bothalia 16,2: 243-249 (1986)

Leaf anatomy of the South African Danthonieae (Poaceae). XV. The

genus Elytrophorus

R. P. ELLIS*

Keywords: Danthonieae, Elytrophorus, leaf anatomy, Poaceae

ABSTRACT

The leaf anatomy of Elytrophorus globularis Hack, and E. spicatus (Willd.) A. Camus is described and illus-

trated from freshly fixed material from SWA/Namibia and Botswana. It is shown that these two species are ana-

tomically indistinguishable. It is suggested that they are conspecific, and that E. spicatus possibly represents juve-

nile plants with immature inflorescences. The anatomical evidence strongly refutes a chloridoid relationship for

Elytrophorus but appears to support arundinoid affinities for the genus. Striking anatomical and ecological simila-

rities exist between Elytrophorus and Sacciolepis huillensis (Rendle) Stapf. No significant leaf anatomical differ-

ences separate Elytrophorus from S. huillensis and some of the other C3 panicoid taxa and, consequently, Elytro-

phorus may represent a link between the Arundinoideae and the Panicoideae.

UITTREKSEL

Die blaaranatomie van Elytrophorus globularis Hack, en E. spicatus (Willd.) A. Camus word beskryf en geillus-

treer deur middel van gefikseerde materiaal afkomstig vanaf SWA/Namibie en Botswana. Daar word getoon dat

hierdie twee spesies anatomies ononderskeibaar is. Daar word voorgestel dat hulle konspesifiek mag wees en dat

E. spicatus net jong plante met onvolwasse bloeiwyse mag verteenwoordig. Die anatomiese bewyse weerle ver-

wantskappe met Chloridoideae vir Elytrophorus maar verwantskappe met Arundinoideae word ondersteun. Dui-

delike anatomiese en ekologiese ooreenkomste tussen Elytrophorus en Sacciolepis huillensis (Rendle) Stapf is

waargeneem. Geen betekenisvolle anatomiese verskille skei Elytrophorus van S. huillensis en sommige van die

ander C3 taksa van die Panicoideae en Elytrophorus mag dus ’n skakel tussen die Arundinoideae en die Panicoi-

deae verteenwoordig.

CONTENTS

Introduction 243

Materials and methods 244

Specimens examined 244

Anatomical description of the genus Elytro-

phorus 245

Leaf in transverse section 245

Abaxial epidermis in surface view 246

Discussion and conclusions 246

Differences between the species of

Elytrophorus 246

Subfamilial and tribal classification 246

General 246

Affinities with the Chloridoideae 247

Evidence from leaf in transverse

section 247

Evidence from abaxial epidermis 247

Affinities with the Arundinoideae 248

Affinities with Sacciolepis and other

C3 Panicoideae 248

Conclusions 248

Acknowledgements 249

References 249

INTRODUCTION

Elytrophorus Beauv. is a genus of unusual little

grasses found in tropical Africa, India to South

China and Australia, with the centre of distribution

apparently in tropical Africa. The genus is therefore

* Botanical Research Institute, Department of Agriculture and

Water Supply, Private Bag X101, Pretoria 0001.

restricted to warm tropical areas of the Old World

surrounding the Indian Ocean.

Some authors have distinguished four species in

the genus (Loxton 1976; Schweickerdt 1942). Other

workers uphold only two species: E. globularis

Hack, and E. spicatus (Willd.) A. Camus (Chippin-

dall 1955; Clayton 1970; Smook & Gibbs Russell

1985). Both these species occur in southern Africa

where they are restricted to the tropical northern-

most parts of the region. In SWA/Namibia, Elytro-

phorus is found in Ovamboland and the Grootfon-

tein, Okahandja and Caprivi Districts, and in Bo-

tswana it occurs in the Mababe Depression and the

Okavango Delta of Ngamiland. E. globularis has

also been collected at Mosdene along the Nyl River

in the Naboomspruit District of the Transvaal.

Both species are water-loving and are found ex-

clusively on the edges of rainwater pans, ponds, de-

pressions and in rice fields, particularly on the pe-

riphery of these shallow water bodies when moist

mud is exposed as the water evaporates and recedes.

Damp hydromorphic clay soil is preferred and the

plants even thrive in the cracking clay. Elytrophorus

can withstand a certain degree of inundation and can

survive in standing water up to 0,2 m deep and is

considered to be a true hydrophyte (Schweickerdt

1942). In ideal situations Elytrophorus can form

dense communities, the individual plants varying in

height from 10 mm to 0,5 m, depending on the pre-

vailing moisture conditions.

Elytrophorus exhibits an unusual combination of

anatomical features which have been described by

Schweickerdt (1942), Jacques Felix (1962), Clifford

& Watson (1977) and Palmer & Tucker (1981). The

244

Bothalia 16,2 (1986)

objective of this paper is to describe and illustrate

the leaf blade anatomy of both species and to relate

this to the anatomical diagnoses of the subfamilies of

the Poaceae as defined by Clifford & Watson (1977)

and Renvoize (1981). The natural relationships of

Elytrophorus are not readily apparent and agrosto-

logists differ as to which subfamily and tribe this

genus should be assigned to. The anatomical evi-

dence will be fully discussed in an attempt to resolve

this question.

MATERIALS AND METHODS

Plants of Elytrophorus were collected in SWA/Na-

mibia and Botswana during the late summers (April

or May) of 1977, 1981 and 1983. Herbarium voucher

specimens were prepared for verification by the Na-

tional Herbarium (PRE). Segments of leaf blade

material were removed in the field and immediately

fixed in FA A (Johansen 1940).

Transverse sections, lOp thick, were prepared

after desilicification in 30% hydrofluoric acid

(Breakwell 1914), dehydration following the method

of Feder & O'Brien (1968) and infiltration and em-

bedding in Tissue Prep (Fisher Scientific). These

sections were stained in safranin and fast green (Jo-

hansen 1940). The manual scraping method of Met-

calfe (1960) was used to prepare scrapes of the abax-

ial leaf epidermis. These were either stained in safra-

nin or double-stained in methylene blue and ruthe-

nium red. The anatomical structure was recorded

photographically using a Reicherdt Univar micro-

scope and Ilford Pan F film (50 ASA).

In the anatomical descriptions which follow, the

standardized terminology of Ellis (1976, 1979) will

be used, together with the following abbreviations:

vb/s - vascular bundle/s

l’vb/s - first order vascular bundle/s

3’vb/s - third order vascular bundle/s

ibs - inner bundle sheath; mestome sheath

obs - outer bundle sheath; parenchyma bundle sheath

Specimens examined:

Elytrophorus globularis

SWA/NAMIBIA. — 1714 (Ruacana Falls): Ovamboland,

Eunda (-DA), Ellis 2586. 1723 (Singalamwe): eastern Caprivi,

Sachona (-CD), Ellis 3705. 1724 (Katima Mulilo): eastern Ca-

privi, Chaka turnoff on Bukalo-Muyako road (-CB), Ellis 3714.

2116 (Okahandja): 32 km N of Okahandja on road to Otjiwa-

rongo (-DB), Gibbs Russell & Smook 5330.

FIGURES l-6.-Leaf blade anatomy of Elytrophorus globularis as seen in transverse section. 1-2, Ellis 2586: 1, leaf margin, x 100;

2, detail of diffuse, semi-radiate chlorenchyma and non-Kranz outer bundle sheath cells, x 250. 3^1, Ellis 2899: 3, lateral part

of lamina with lacunae between all vascular bundles, x 100; 4, detail of lacuna, chlorenchyma and first order vascular bundle,

x 400. 5-6, Gibbs Russell & Smook 5330: 5, outline with triangular adaxial ribs, x 100; 6, diffuse chlorenchyma, lacuna and

colourless bundle sheath cells, x 400.

Bothalia 16,2 (1986)

245

FIGURES 7-12. — Abaxial epidermis of Elytrophorus globularis. 7, Ellis 2904 showing costal and intercostal zones, x 160. 8, Ellis

2900, phase contrast with nodular silica bodies, stomata, microhairs and intercostal long cells, x 400. 9-10, Ellis 2586:

9, costal and intercostal zones and stomatal distribution, x 250; 10, note silica bodies, stomata, microhairs and long cells, x

400. 11, Ellis 3705, nodular silica bodies and microhairs, x 400. 12, Ellis 3714, detail of epidermal cells, x 400.

BOTSWANA. — 1824 (Kachikau): Chobe National Park,

Goha Hills (-AC), Ellis 2914. 1924 (Joverega): 100 km N of

Maun on road to Moremi (-AC), Ellis 2904. 2023 (Kwebe Hills):

Samedupe Drift over Botletle River (-BA), Ellis 2899, 2900.

Elytrophorus spicatus

SWA/NAMIBIA. — 1724 (Katima Mulilo): eastern Caprivi,

Salambala between Bukalo and Ibbu (-DA), Ellis 3718.

BOTSWANA. — 1824 (Kachikau): Chobe National Park,

Goha Hills (-AC), Ellis 2913.

ANATOMICAL DESCRIPTION OF THE GENUS

ELYTROPHORUS

Leaf in transverse section

Outline-, expanded, broadly V-shaped. Ribs and

furrows ; rounded adaxial ribs present over all vbs

(Figures 1-3; 13-14); sometimes somewhat triangu-

lar (Figure 5); all ribs of similar size. Shallow, wide

furrows between all vbs (Figures 1-5; 13-14). Abax-

ial surface without undulations. Median vascular

bundle: no structurally distinct midrib present (Fig-

ures 5 & 13). Vascular bundle arrangement : 5 Fvbs

in leaf section; 1 3’vb between consecutive l'vbs; no

2’vbs. All vbs situated in centre of blade (Figures 2,

4 & 14) except in specimen with triangular ribs (Fig-

ure 5). Vascular bundle description: 3’vbs elliptical

and angular; l’vbs elliptical to round; phloem ad-

joins ibs; metaxylem vessels narrow and round. Vas-

cular bundle sheaths: obs round, entire; sometimes

with slight adaxial extensions (Figures 2, 4, 6 & 14).

Obs cells round, irregular in size, with thin walls and

containing few or no chloroplasts. Ibs entire without

wall thickenings. Sclerenchyma: small adaxial and

abaxial strands associated with all vbs; abaxial strand

usually in contact with the obs (Figures 2, 4, 6 & 14).

Small cap in margin (Figures 1, 3 & 13). Mesophyll:

246

Bothalia 16,2 (1986)

diffuse chlorenchyma tending to radiate condition

around vbs; lateral cell count greater than 4; central

cells very diffuse and irregular tending to break

down into lacunae (Figures 4 & 6) which are then

located between all vbs. No colourless cells present.

Adaxial epidermal cells : small groups of bulliform

cells located at the bases of all furrows. Epidermal

cells thin-walled and inflated; a few prickles asso-

ciated with ribs. Abaxial epidermal cells : thin-

walled, inflated with thin cuticle; no epidermal ap-

pendages.

Abaxial epidermis in surface view

Intercostal long cells : very elongate (Figures 8, 9 &

15), not rectangular but side walls slightly angled

outwards and cell narrowing toward end walls; anti-

clinal walls unthickened and very slightly undulating

(Figures 10 & 15); adjoin one another or separated

by stomata or microhairs (Figures 8, 10 & 15). Sto-

mata: low dome-shaped (Figures 8, 10 & 15); 4 or 6

files per intercostal zone but absent in centre of

zones; rows of stomata adjacent to one another (Fig-

ure 10); usually 1, sometimes 2 interstomatal long

cells between successive stomata in file. Intercostal

short cells: absent. Papillae: absent. Prickles: not

present on abaxial surface. Microhairs: bicellular;

very short basal cell and long tapering distal cell

(Figures 8, 10, 11, 12 & 15); hairs slightly longer

than stomata; present on edges and centre of inter-

costal zones. Macrohairs: absent. Silica bodies: cos-

tal; elongated nodular (Figure 8) to almost sinuous

and crenate (Figures 11, 12, 15 & 16); in pairs or

separated by short cells; granules often present. Cos-

tal zones: 1, 3 or 5 cells wide; files with silica bodies

alternating with files of costal long cells; these very

narrow and long.

DISCUSSION AND CONCLUSIONS

Differences between the species of Elytrophorus

In his treatment, Schweickerdt (1942) considered

the genus Elytrophorus to comprise four species: E.

globularis and E. spicatus as well as E. africanus

Schweick. and E. interruptus Pilg. The latter two

species are now considered to be synonyms of E.

globularis (Clayton 1970) and consequently, the

present study includes the two species which repre-

sent all currently recognized members of the genus.

The anatomical details described by Schweickerdt

(1942) agree closely with the observations of this

study. The only significant departure concerns the

mention of aerenchymatous cells traversing the lacu-

nae. Schweickerdt considers this tissue to be a strik-

ing characteristic of the genus. In the present study,

however, no aerenchyma or stellate cells were ob-

served in any of the ten specimens examined. Most

specimens had lacunae located between the vascular

bundles (Figures 3-6) but these cavities were never

seen to be traversed by colourless aerenchyma cells.

In addition, in some specimens of both species, the

lacunae were not even fully developed (Figures 1 &

2, 13 & 14) although the central mesophyll between

the vascular bundles was more diffuse, with larger

intercellular air spaces appearing to represent the in-

itial stages of cellular breakdown prior to the forma-

tion of the typical lacunae. If this is so, then the lacu-

nae of Elytrophorus are lysigenous cavities arising by

the dissolution of entire cells during the later ontoge-

netic stages of the leaf. The replacement of these

broken down mesophyll cells by aerenchyma cells at

this late stage of leaf differentiation appears un-

likely.

Schweickerdt (1942) mentions aerenchyma tissue

in all four species he studied although the cells are

only illustrated in E. spicatus. The specimens exam-

ined by him were prepared from dried herbarium

material and he remarks that tissue recovery was not

satisfactory and this is reflected in his camera lucida

drawings. His details and measurements of the softer

tissues, in particular, may not necessarily be reliable

and accurate.

This may also explain another difference between

the findings of this study and those of Schweickerdt

(1942). In the latter study diagnostic anatomical dif-

ferences were detected between E. globularis and E.

spicatus whereas in the present study no differences

were observed. According to Schweickerdt (1942),

E. spicatus is characterized by having a leaf blade of

0,3-0,36 mm thick, with both adaxial and abaxial

ribs and furrows and with bulliform cells between all

bundles. E. globularis is said to differ in having a

thinner blade (0,15-0,28 mm), neither surface being

ridged, and well developed bulliform cells only oc-

curring in the region of the midrib. This interspecific

variation appears to be contradicted by the illustra-

tion of E. globularis (Jacques Felix 1962), which

shows large triangular adaxial ribs as well as lacunae,

whereas an illustration of E. spicatus (Clifford &

Watson 1977) shows neither ribs nor lacunae. In the

above studies only a single specimen from each

species was examined and intraspecific variation

could not be ascertained with much confidence. In

the present study, however, variation has been

shown to occur within each of the species and the

sample of each species studied exhibited as much va-

riation as that considered by Schweickerdt (1942) to

justify separation of the two species. Examples are,

as mentioned, the differences in adaxial rib and la-

cuna development in different specimens of E. glob-

ularis (Figures 3 & 5).

The present study shows that E. globularis and E.

spicatus are indistinguishable on anatomical

grounds. These results, and the observation that

both species may occur at the same locality at the

same time, throw doubt on the validity of upholding

two separate species. E. spicatus may merely repre-

sent juvenile plants with younger or immature inflo-

rescences. This hypothesis requires testing.

Subfamilial and tribal classification

General

The classification of Elytrophorus has been the

subject of much debate in the literature. Some

authors consider it to belong to the Chloridoideae,

and Chippindall (1955) and Bor (1960) placed Ely-

trophorus in the Eragrostideae. Clifford & Watson

(1977) place it in their chloridoid group although

they do note that the leaf anatomy is atypical, dis-

Bothalia 16,2 (1986)

247

FIGURES 13-16. — Leaf anatomy of Elytrophorus spicatus. 13-15, Ellis 2913 : 13, leaf outline, x 100; 14, detail of semi-radiate

mesophyll and vascular bundles, x 400; 15, abaxial epidermis with nodular silica bodies, stomata and long cells, x 400.

16, Ellis 3718, abaxial epidermis, x 400.

playing a curious mixture of festucoid and panicoid

features as well. Prat (1960) and Decker (1964)

placed Elytrophorus in their unplaced genera al-

though Decker noted similarities with the Dantho-

nieae. Jacques Felix (1962) isolated the genus in a

separate tribe, the Elytrophoreae, belonging to his

series the Arundinoidae. This classification has been

upheld by most modern authors and Elytrophorus is

usually assigned to the Arundinoideae in the tribe

Danthonieae (Clayton 1970; Loxton 1976) or the

tribe Arundineae (Renvoize 1981). Renvoize (1981)

considers Elytrophorus to conform closely to the

coherent arundinoid core group which is virtually

synonymous with the Danthonieae.

Affinities with the Chloridoideae

Evidence from leaf in transverse section

Elytrophorus has a double bundle sheath, as do

the chloridoid grasses, but the outer sheath is thin-

walled and non-Kranz, lacking specialized chloro-

plasts. It is therefore a C3 genus, as is confirmed by

13C/12C ratios for E. globularis of -26,23% ( Dinter

7390) and E. spicatus of -25,70% ( Schweickerdt

2089). As far as is known, all chloridoid grasses are

C4with only one possible exception (Ellis 1984) and

therefore, have strongly radiate mesophyll and a

maximum lateral cell count of less than four. In Ely-

trophorus this count is greater than 10 and, although

the mesophyll displays a tendency to be radiate, it is

of the Isachne type (Metcalfe 1960) with several lay-

ers of elongated, diffuse cells with many air spaces

all arranged in a somewhat radiate manner (Figures

2 & 14). This type of mesophyll is unknown in the

Chloridoideae where a single layer of compact, tabu-

lar cells surrounds each bundle. In the chloridoid

type of anatomy the bulliform cells are usually asso-

ciated with deeply penetrating fans of colourless

cells, whereas in Elytrophorus none of these colour-

less cells occur. The evidence from leaf transections

does not indicate a chloridoid connection for Elytro-

phorus.

Evidence from abaxial epidermis

Elongated microhairs with short basal cells, and

much longer, tapering distal cells are common in

Elytrophorus and were observed on all specimens

examined in this study. The structure of these micro-

hairs is illustrated in the accompanying photomicro-

graphs (Figures 8, 10, 11, 12, 15 & 16) and even

more clearly in the scanning electron micrographs of

Palmer & Tucker (1981). This structure differs sig-

nificantly from the chloridoid type which is always

egg-shaped with shorter, inflated distal cells (Clif-

ford & Watson 1977; Renvoize 1981). Elytrophorus

also lacks long cells with sinuous walls w'hich are typ-

ical of chloridoid grasses. The subsidiary cells of Ely-

trophorus are dome-shaped (Figure 10) or low

dome-shaped (Figures 8, 12 & 15), whereas in the

Chloridoideae they are predominantly triangular.

Chloridoid grasses often have papillate epidermides

whereas Elytrophorus does not, at least at the level

of resolution of light microscopy. Palmer & Tucker

(1981) illustrate tiny, warty papillae visible only at

higher magnifications with the scanning electron

microscope but these are, nevertheless, not of the

chloridoid type. The horizontally elongated nodular

to sinuous type of silica body found in Elytrophorus

is unknown in the Chloridoideae where silica bodies

are not elongated and are usually saddle-shaped, but

may be cross-shaped, square or shortly dumbbell-

shaped. In epidermal structure, therefore, Elytro-

248

Bothalia 16,2 (1986)

phorus bears no resemblance whatsoever to the

chloridoid condition.

Leaf anatomical evidence, therefore, does not

support chloridoid phylogenetic affinities for Elytro-

phorus and the classification of this genus in the

Chloridoideae cannot be supported.

Affinities with the Arundinoideae

Other workers place Elytrophorus in the rather ill-

defined subfamily Arundinoideae (Jacques Felix

1962; Clayton 1970; Renvoize 1981). This subfamily

cannot be defined as precisely as the other four sub-

families and lacks reliable diagnostic features.

Nevertheless, a diagnosis of the Arundinoideae is

possible (Clifford & Watson 1977; Renvoize 1981)

and, in most respects Elytrophorus conforms very

well to this definition.

Arundinoid microhairs are finger-like with taper-

ing distal cells, the subsidiary cells are domed and