PROCEEDINGS -

MC7Z

| IY

of the

San Diego Society of Natural History

jl VS ENC

Founded 1874

Number 35

31 July 1999

The Flora of Caién de Nacapule: A Desert-Bounded Tropical Canyon

near Guaymas, Sonora, Mexico

Richard S. Felger

Drylands Institute, 2509 North Campbell Avenue PMB 405, Tucson, Arizona 85719

ABSTRACT.—Caiion de Nacapule, located at the southeastern flank of the Sierra El Aguaje, is about 20 km northwest of Guaymas, Sonora, Mexico,

in the Sonoran segment of the Gulf Coast subdivision of the Sonoran Desert. The climate is arid with highly variable biseasonal rainfall (winter,

summer). Many plants of tropical origin reach their northern limits in this region or do not extend farther north into the arid coastal Sonoran Desert. The

vegetation in the canyon is tropical thornscrub and approaches the character of tropical deciduous forest in the wettest areas. The Nacapule flora,

species found in the canyon and within 500 m of the canyon mouth, includes 285 species of vascular plants in 215 genera and 65 families. The most

diverse families are the Asteraceae, Fabaceae, Poaceae, and Euphorbiaceae. Regional endemics limited to the Sierra E] Aguaje and nearby mountains

include Telosiphonia nacapulensis and Verbesina felgeri. Geographically isolated populations of tropical genera such as Aphanosperma, Briquetia,

Coccoloba, Ficus, and Zanthoxylum also occur in the canyon. Plants not native to the Guaymas region, mostly Old World weeds, are represented by 17

species. There is habitat degradation at Nacapule but much original vegetation remains. This unique canyon is worthy of vigorous protection.

RESUMEN.— El Caiién de Nacapule, localizado en el lado Sureste de la Sierra El Aguaje, aproximadamente 20 km al Noreste de Guaymas en el

Estado de Sonora, México, se encuentra incluido en la parte sonorense de la subdivisién de la Costa del Golfo del Desierto Sonorense. El clima es arido

con precipitacién altamente variable distribuida en dos temporadas (invierno y verano). Muchas plantas de origen tropical alcanzan sus limites

nortefos en esta region del Desierto Sonorense. La vegetacion en el cafién esta formada por matorral espinoso tropical, el cual muestra caracteristicas

de bosque tropical deciduo en las areas mas himedas. La flora de Nacapule, desde 500 m de la boca del cation hasta el fondo del mismo, incluye 285

especies de plantas vasculares en 215 géneros y 65 familias. Las familias mas diversas son Asteraceae, Fabaceae, Poaceae, y Euphorbiaceae. Entre las

endémicas limitadas a las cafiones de la Sierra El] Aguaje se incluyen Verbesina felgeri y Telosiphonia nacapulensis. También se encuentran en el canon

poblaciones geograficamente aisladas de especies pertenecientes a géneros tropicales, como Aphanosperma, Briquetia, Coccoloba, Ficus, y Zanthoxy-

lum. Las plantas no nativas a la regidn de Guaymas, la mayoria hierbas del Viejo Mundo, se encuentran representadas por 17 especies. Aunque existe

degradacion del ambiente en Nacapule, mucha de la vegetaci6n original todavia permanece. Este singular cafion es digno de proteccion efectiva.

INTRODUCTION

Canoén de Nacapule has a rich flora and a history of botanical

collections spanning more than a century. This desert-bounded tropi-

cal canyon is 6 km north of the burgeoning beach resorts of San

Carlos, or 20 km northwest of Guaymas (Fig. 1). The canyon en-

trance is at 28° 00'56" N, 111° 02'58” W and an elevation of ap-

proximately 150 m. From one end to the other the canyon floor prob-

ably rises less than 25 m (Fig. 2). Only about 1.2 km long, Nacapule

Canyon slices into the southeastern flank of the Sierra E] Aguaje [the

region called the Guaymas Monadnoc by Gentry (1949)]. Ragged

red and yellow rhyolite slopes rise steeply from the bajada plain to a

peak elevation of ca. 860 m. This study includes the canyon bottom,

the immediate slopes, and the adjacent open desert within about 500

m of the canyon entrance, as well as adjacent Nacapule Spring.

Nacapul is the term in the Cahitan (Yaqui and Mayo) language for

earlobe (naca = ear) and one of the native figs, Ficus pertusa.

On my first trip to the area in the early 1960s I camped beneath a

lone Sabal palm on the cobble beach by the yet undeveloped Bahia

San Carlos. Jestis Ortega, a cowboy from a nearby ranchito, took me

by horse to see the cool, green canyon. He said it was named for the

huge nacapule tree at the spring just north of the canyon mouth. We

drank from the water and found two boa constrictors mating among

the dry, crackling fig leaves. Cattle had muddied the ground around

the wooden water trough. We rode into the deep canyon, green like

the tropics, shaded in the late afternoon of a hot summer day. Palms

overtopped the trees and marched up rugged rhyolite walls; fig trees

hung from cliff faces. We stopped to roll cigarettes. Jesus was proud

of the mystic gorge turning purple in the hazy dusk.

Since that time substantial changes have been wrought on the

region and the canyon, but much of the original vegetation remains.

The uppermost reaches of the canyon and the rough slopes, difficult

to climb and inaccessible to cattle, are in pristine condition.

The canyon cuts into Tertiary volcanic rock of the Cerro

Algodones group, of which most of the Sierra El Aguaje is composed

(Wilson 1978). The Cerro Algodones group consists of silica-rich

lavas and tuffs of rhyolite to rhyodacite. The tuff may be more per-

meable than lava and has commonly been altered by the circulation

of hot water. As a result the tuff weathers to yellowish colors, con-

trasting with the reddish brown lavas. The lava is massive, flow-

banded, and glassy. The Sierra E] Aguaje is part of a much larger

volcanic field in which gigantic eruptions resulted in the collapse of

Richard S. Felger

Fa SN Se hanes

Be)

<4’ GUAYMAS

eae

BAHIA SAN CARLOS

Figure 1. Cafén de Nacapule and surrounding region. Map by Jim Abbott, SciGraphics.

calderas tens of kilometers across. The north-south segment of the

canyon is cut into a post-collapse rhyolitic volcanic vent on a caldera

margin. At the canyon mouth, the drainage passes from volcanic rock

into Quaternary alluvium consisting of unconsolidated sand and

gravel derived from the mountains.

The climate is arid. Rainfall is biseasonal and highly variable.

Winter—spring rains, derived from Pacific frontal storms, can deliver

light rains or drizzle over many hours. Summer rains result from an

abbreviated monsoon of tropical origin and often bring violent, local

thunderstorms with dramatic lightning and heavy if brief rainfall.

These sporadic rains may commence about one or two months after

summer solstice and continue into September. In some years either

the summer or winter rains may be very scant or fail entirely. Tropi-

cal storms or chubascos sometimes bring large amounts of rain in

late summer or early fall. These occasional hurricane-fringe storms

may induce spectacular growth of many perennials. Winters are mild

and warm, most of the region, and presumably the canyon, being

nearly frost free. Coconuts and other tropical plants are grown in

nearby San Carlos. The hot weather and seasonal drought of late

spring and early summer is severely limiting to the plant life. The

summers are long and very hot.

Shreve (1951) designated the vegetation of the region as the

Sonoran segment of the Gulf Coast subdivision of the Sonoran

Desert. The higher elevations of the Sierra El Aguaje, especially on

north-facing slopes, and many of the riparian habitats support veg-

etation that can be classified as foothills thornscrub, sometimes ap-

proaching tropical deciduous forest in character (Felger 1966; Felger

and Lowe 1976; Burquez et al.).

Nacapule is among the several large canyons in the Sierra El

Aguaje that support a rich, subtropical flora and vegetation. High,

rugged desert mountains separate two nearby canyons that are com-

parable to Nacapule. Cafién Las Barajitas, approximately 15 km

northwest of Nacapule, is more than 8 km long and drains from the

western side of the Sierra E] Aguaje to the Gulf of California. Its flora

includes more than 225 species of vascular plants (pers. obs.). The

long Cafién Los Anegados drains eastward from near the center of

the Sierra E] Aguaje through the ranch and waterhole known as

Aguaje Robinson. Although only 6 airline km to the northwest,

Robinson is inaccessible by trail or road from Nacapule. Anegados

appears to have a species richness comparable to that of Nacapule

but remains scarcely explored botanically. Among the special plants

occurring at some or all of these canyons are Coccoloba goldmanii,

Vallesia laciniata, Verbesina felgeri, and Zanthoxylum mazatlanum.

Some of the unusual plants also should be sought in similar habitats

at higher elevations in the Sierra E] Aguaje and the Sierra Libre [ca.

60 km to the northeast, east of the highway (Mexico 15) to

Hermosillo; see Yetman and Burquez (1996)]. Despite more than

one century of extensive botanical collections in the Guaymas re-

gion, the higher elevations of the Sierra El Aguaje and Sierra Libre

remain botanically unexplored.

Many plants of tropical origin reach their northern limits in this

region, or they do not extend farther north into the arid, coastal

Sonoran Desert, e.g., Citharexylum, Coccoloba, Coursetia caribaea,

Dalechampia, Desmodium, Ficus insipida, F- pertusa, Hintonia,

Ludwigia octovalvis, Randia sonorensis, and Sida hyalina. Sonoran

Desert plants reaching their southern limits in this region include

The Flora of Canon de Nacapule: A Desert-Bounded Tropical Canyon near Guaymas, Sonora, Mexico 3

sit.

Figure 2. Canon de Nacapule, looking westward from near the mouth of the canyon.

Abutilon parishii, Colubrina californica, Fouquieria splendens, and

Perityle emoryi. Among species with geographically isolated popu-

lations are Aphanosperma sinaloensis, Briquetia sonorae, Coccoloba

goldmanii, Ficus insipida, Psilotum nudum, and Zanthoxylum

mazatlanum. Others occur primarily on the Baja California penin-

sula and are otherwise found only in the Sierra El Aguaje, e.g., Eu-

phorbia ceroderma, Pluchea salicifolia, and Washingtonia robusta.

Regional endemics include Brickellia rhomboidea, Echinocereus

engelmannii subsp. llanurensis, Euphorbia pediculifera var.

linearifolia, Perityle leptoglossa subsp. palmeri, Physalis purpurea,

Telosiphonia nacapulensis, and Verbesina felgeri.

A stream flows all year in the upper part of Canon de Nacapule

(Fig. 3) or in drought dries to scattered seep-filled pools. In the 1960s

the stream flowed intermittently through the lower part of the canyon

but today flows only with rainy weather or seasons. Destruction of

portions of the wetland vegetation and understory vegetation, mostly

due to decades of cattle grazing, seems to have contributed to reduc-

tion of the stream flow. Exposed roots of some of the larger Washing-

tonia palms indicate that the canyon floor has eroded approximately

1.5 m during the lifetime of these palms. The lower part of the can-

yon runs more or less east-west for nearly | km, and the high, north-

facing canyon wall and mountain slope shade much of the lower

canyon during the winter. The Sierra El Aguaje endemics and geo-

graphically isolated populations of tropical species such as Aphano-

sperma sinaloensis, Briquetia sonorae, Coccoloba goldmanii,

Verbesina felgeri, and Zanthoxylum mazatlanum occur in this shaded

habitat.

In 1965 I recorded the plants in a 5 x 50 m quadrat in this unusual

habitat, finding 41 species (Table 1). The quadrat could not be made

larger because of constraints of the topography. A road now virtually

obliterates the quadrat site. An additional 14 species occurred on the

canyon floor within 5 m of the quadrat, and more species were

quickly encountered as one walked through the canyon. I estimated

plant coverage here at 98%. Large shrubs and small trees produced a

closed canopy with crown heights generally at 4 to 6 m. The vegeta-

tion was weakly stratified into tree, shrub, and ground-herb layers

and interlaced by vines and scandent shrubs. Coverage consisted

Figure 3. Washingtonia robusta along streambed in the upper portion of

the canyon. The exposed root masses indicate the soil has eroded more than

1.5 m. January 1996.

4 Richard S. Felger

TABLE |. Plants in a5 x 50-m quadrat ca. 0.5 km from entrance to

Canon de Nacapule, January, 1965., on canyon bottom, ca. 0.5 km

from canyon entrance“.

Number Maximum Mean

of height height

Species’ plants (ft) (ft)

Non-herbaceous plants

Brahea elegans 3 PPS) 19.3

Sapindus saponaria 3 24.6 20.0

Celtis reticulata 21.0 —

Lysiloma divaricatum© —_— 20.0 —

Forchhammeria watsonii 18.2 —

Cordia sonorae 2 16.1 14.3

Passiflora mexicana 14.9 —

Sebastiania bilocularis 4 1349) 11.5

Sideroxylon occidentale© — 13.9 —

Celtis pallida® — 13.4 —

Hintonia latiflora 13.2 —

Haematoxylum brasiletto 1 12.9 _

Prosopis glandulosa© — 12.8 —

Coccoloba goldmanii 3 12.0 10.1

Coursetia glandulosa 19 12.4 iil

Gouania rosei© — Nils? —

Guaiacum coulteri 2 it 10.1

Vallesia laciniata 13 11.1 9.9

Antigonon leptopus 33) 10.8 —_

Justicia californica 2 10.8 —

Nissolia schottii | 10.6 —

Phaulothamnus spinescens 7 10.3 8.3

Acacia willardiana 3 9.8 —

Jacquinia macrocarpa 2 9.6 8.9

Marsdenia edulis 2 9.0 eS)

Randia sonorensis 2 9.0 8.1

Cardiospermum corindum 3 U3} _—

Cocculus diversifolius© — Voll

Randia thurberi l 6.4 —

Zapoteca formosa 8 6.3 5.5

Ibervillea sonorae | 6.2 oo

Mimosa distachya° — 6.2 —

Ambrosia ambrosioides© —- 4.9 —

Acalypha californica 2 4.7 4.5

Justicia candicans 16 4.6 3.8

Trixis californica’ 4.5 —

Brickellia coulteri 4.1 3.6

Ditaxis lanceolata© _

Bursera laxiflora 2

Dodonaea viscosa® _—

Coursetia caribaea 5 3.9 =

Tragia jonesii |

Ambrosia cordifolia |

Vaseyanthus insularis —

Abutilon incanum 1

Callaeum macropterum‘ I

Elytraria imbricata 2

Hofmeisteria crassifolia —

Plumbago scandens |

Total 168

SEK KH VV w

Re Why

Herbaceous plants

Dryopetalum runcinatum

Euphorbia setiloba

Perityle californica

P. leptoglossa

unidentified perennial forb

“Deep rocky and gravelly soil, much leaf litter, and limited cattle grazing;

plant coverage ca. 98%.

Total species in 0.25-ha quadrat: 41. Total species in stand (canyon floor

within 5 m of quadrat): 55

“Canyon-floor plant within 5 m of quadrat.

mostly of large, spreading shrubs, e.g., Coccoloba goldmanii,

Coursetia glandulosa, and Vallesia laciniata. The 11 species of

vining plants included Antigonon leptopus, Gouania rosei, and

Passiflora mexicana. Arborescent species along the canyon floor are

generally scattered in small groves or groups of several adult indi-

viduals. The vegetation cannot be characterized by any one or sev-

eral species.

The Nacapule flora includes 285 species of vascular plants in 215

genera and 65 families. The most diverse families are the Asteraceae,

Fabaceae, Poaceae, and Euphorbiaceae (Table 2). Fourteen genera

have three species each, and only Euphorbia, with six species, is

more diverse.

The Nacapule flora contains about half the number of species in

the entire flora of the coastal +85 km from the vicinity of Tastiota to

Las Guasimas—a region of more than 3000 km? with Guaymas and

San Carlos at its center (Felger 1966; unpublished notes). The

Nacapule flora represents approximately 11.8% of the total flora (ca.

2500 species) of the 300,000-km? Sonoran Desert (Shreve 1951,

Wiggins 1964). The topography is complex, and although there are

also other topographically complex riparian canyons in the region

they apparently do not support so many species in such a small area.

I know of no other place in the Sonoran Desert where the species

richness 1s so great as in Canon de Nacapule.

The upper part of the canyon turns sharply northward so that its

axis is north-south. At this bend there is a narrow side canyon ex-

tending up the east face of the mountain, providing substantial drain-

age into the lower canyon. There are many small, permanent shallow

pools and hidden, trickling seeps along the shaded bottom of the

upper canyon. Plants more or less restricted to this part of the canyon

include the tall fan palm Washingtonia robusta, the large fig Ficus

insipida, and a number of herbaceous wetland species such as

Eleocharis geniculata, Fuirena simplex, Ludwigia octovalvis, and

Mimutlus floribundus.

In contrast to the verdant canyon floor, the canyon walls are, in

places, partially barren. Hesper palms (Brahea elegans) grow from

crevices in sheer cliffs and rock slopes above the canyon floor. Other

common rock-adapted plants clinging to cliffs and rocky slopes in-

clude Agave chrysoglossa, Asclepias leptopus, Ficus palmeri,

Hofmeisteria crassifolia, Perityle leptoglossa, and Pleurocoronis

laphamioides. On the slopes of more gentle gradients with a soil pro-

file there are dense stands of shrubby vegetation ranging to near 100%

cover. Vegetation on north- and east-facing slopes is relatively dense

and verdant, resembling foothills thornscrub or tropical deciduous for-

est vegetation found to the east and south of the Sonoran Desert. Veg-

etation on the more arid, south-facing canyon slope supports Sonoran

Desert elements such as palo blanco (Acacia willardiana), foothills

palo verde (Parkinsonia microphylla), and desert ironwood (Olneya

tesota). Vegetation on desert slopes away from the canyon generally

resembles that of the south-facing canyon side.

The open desert on the bajada adjacent to the canyon supports a

perennial vegetation cover of about 50%, although summer-fall

TABLE 2. Seven largest families of

the flora of Canon de Nacapule.

Family Genera Species

Asteraceae 26 31

Fabaceae 26 31

Poaceae 1S 19

Euphorbiaceae 9 16

Cactaceae 9 13

Malvaceae 8 11

Acanthaceae 7 10

The Flora of Canon de Nacapule: A Desert-Bounded Tropical Canyon near Guaymas, Sonora, Mexico

ephemerals may carpet the ground with essentially 100% cover. Win-

ter—spring ephemerals are concentrated near the larger perennials such

as desert ironwood (Olneya tesota). These larger desert shrubs and

small trees provide shade, perhaps extra nutrients, and protection from

grazers, producing “island patches” (Burquez and Quintana 1994).

Many of the large, xerophytic shrubs and small trees on the open

desert and canyon floor near the entrance tend to be set well apart

from each other, while smaller and seemingly shorter-lived and

quicker-growing shrubs have aggregated patterns of distribution.

This pattern seems at least in part to be the result of cattle grazing.

Among the most common and conspicuous larger xerophytic peren-

nials are Bursera microphylla, Fouquieria diguetii, F: macdougalii,

Colubrina glabra, Forchhammeria watsonii, Jatropha cuneata, Mi-

mosa distachya, Olneya tesota, and Ruellia californica.

Arroyo Nacapule leads southeastward from the canyon entrance

and courses through the bajada desert plain for several kilometers.

Cut about 8+ m deep with steep walls, it supports some of the un-

usual Nacapule plants, e.g., Serjania palmeri, Zanthoxylum fagara,

scattered palms (Brahea elegans and Sabal uresana), and a few fairly

large trees of Ficus palmeri.

The flora of the Nacapule region is dynamic, with immigrations

and departures. My observations indicate that most changes are an-

thropogenic. Plants not native to the Guaymas region, mostly Old

World weeds, are represented by 16 species, e.g., Malva parviflora,

Sisymbrium irio, and Pennisetum ciliare. Nonnative plants are iden-

tified by an asterisk (*). Others, such as Acacia cochliacantha, Opun-

tia fulgida, and Vallesia glabra are native to the Guaymas—San Carlos

region but are apparently not part of the original Nacapule flora. Sev-

enteen species, or 6% of the total flora, seem to have spread to the

canyon and spring area, or at least have substantially increased in

population size, within the past two decades as a result of the activi-

ties of cattle and other habitat disturbances such as roads, collecting

of decorative rock, and trampling by too many visitors:

Acacia cochliacantha

A. farnesiana

Ambrosia confertiflora

Baccharis sarothroides

*Chenopodium murale

*Conyza canadensis

*Dactyloctenium aegyptium

*Digitaria ciliaris

Gymnosperma glutinosum

*Lactuca serriola

*Malva parviflora

Opuntia fulgida

*Pennisetum ciliare

Prosopis glandulosa

*Rhynchelytrum repens

*Sisymbrium irio

Vallesia glabra

The changes attributed to cattle grazing are based on my numer-

ous visits and observations, including comparing grazed areas with

adjacent areas inaccessible to cattle. Although subjective, I noted

“new” plants and changes whenever possible. Amaranthus watsonti

seems to have increased along the canyon floor in areas of cattle

grazing. A few wetland plants that are probably bird-dispersed seem

to be transient and not fully established, e.g., Echinodorus berteroi,

Limnocharis flava, and Typha domingensis. Four species, Cyperus

squarrosus, Fimbristylis annua, Heliotropium procumbens, and

Psilotum nudum, are apparently no longer present in the canyon.

Fimbristylis may have been eliminated by cattle grazing. Psilotum,

stunted at the time of discovery, may have succumbed to drought.

The other two were probably not well established in the canyon.

The growth-form spectrum of the Nacapule flora is shown in

Fig. 4. Trees are represented by 18 species (6% of the flora), larger

shrubs or vines by 36 species (13%). In comparison, tree species

120

100

3 80

”

xe}

8 60

re)

Geophytes

Epiphytes

Phanerophytes

Chamaephytes

Hemicryptophytes

Hydrophytes

Figure 4. Growth-form spectrum of the Nacapule flora. Phanerophyte:

Trees, shrubs, or vines with growth buds well above ground. ME, mega—

phanerophytes (trees >5 m tall); MI, microphanerophytes (larger shrubs or

vines, usually 2—5 m tall); NA, nanophanerophytes (shrubs, vines, or shrub-

sized perennials, usually 0.2—2 m tall). Chamaephyte: Perennials with mer-

istem above ground but below 0.5 m. Hemicryptophyte: Perennials with mer-

istem at or near ground level. Geophyte: Meristem below the ground.

Therophyte: Annuals or ephemerals. TN, nonseasonal therophytes; TS, sea-

sonal summer-fall therophytes; TW, seasonal winter-spring therophytes.

Hydrophyte: Meristem in water. Epiphyte: Plants entirely above ground.

likewise represent 6% of the flora of the northern Sierra Madre Occi-

dental as well as that of the state of Sonora (Felger and Johnson

1995; unpublished data). The largest groups are shrub-sized perenni-

als (68 species, 24%) and annuals (72 species, 25%). Only two spe-

cies are geophytes, 1.e., Aristolochia watsonii and Commelina erecta.

The three species of epiphytes are parasitic plants in the Loranthaceae

and Viscaceae. The growth-form spectrum for the Nacapule flora is

characteristic of regions intermediate between the dry tropics (e.g.,

tropical deciduous forest) and warm deserts (Burquez et al. 1999).

Vining plants, usually relatively few in desert regions, are repre-

sented by 26 species (9%). Plants with succulent stems and/or leaves

include 25 species (9%). These range from small annuals such as

Portulaca to giant cacti such as card6n (Pachycereus pringlei). Suc-

culents are especially prominent on exposed rock slopes and hilltops

with very shallow or no soil.

Wetland plants of tropical as well as temperate origin occur along

the permanent stream. Tropical vines grow through the shrubs and

small trees, lacing into gallery groves of tall palms. Three species of

fig (Ficus) and three genera of native palms make up part of the

riparian streambed flora. One of these figs, Ficus insipida, forms

buttress roots, a growth habit unique for the Sonoran Desert.

The collection history of Canon de Nacapule spans more than

one century and includes a number of prominent western botanists

(Table 3). Four species have been described from specimens from

the canyon: Erythea clara (Brahea elegans), Telosiphonia nacapu-

lensis, Vallesia baileyana (V. laciniata), and Verbesina felgeri.

CONSERVATION

Bahia San Carlos is a major resort area with hotels, vacation homes,

olf courses, and marinas. Most of the original vegetation is destroyed,

Lt fo]

6 Richard S. Felger

TABLE 3. Collectors of botanical specimens from Caién de Nacapule.

Martha Ames [Martha Burgess, Martha Wiseman], 12 Mar 1977, with Bonnie

Fine.

Liberty Hyde Bailey, 30 Mar 1934, 14 Apr 1934, and 14 Apr 1936 (Bailey

1937, BH, MO).

C. David Bertelsen, 6 Nov 1992, with John F. Wiens and Kristen J.

Johnson

Fredrick C. Boutin, Jan—Feb, 1970, with Fred Brandt; Feb 1970, with

Myron Kimnach (HNT).

Tony L. Burgess, 24 Aug 1984, with Peter Warshall.

Thomas F. Daniel, 12 Jan 1982 (ASU).

Richard Felger, 18 June 1960, with Jesus Ortega; 13 Oct 1960; 1963, with

Alexander Russell and Robert Russell; 11 Jan 1965, with Robin Thomas; 7

Sep 1980, with Robert Schmalzel; 19 Oct 1984, with James Aronson and

Avi Shmida; 19 Nov 1984, with Diego Valdez Zamudio; 25 Feb 1985,

with Robert S. Devine; 9 Mar 1985, with Goodman Larson and Jean

Russell; 11 Aug 1985, with Mark A. Dimmitt; 10 Oct 1985, with Frank

Reichenbacher; 13 Dec 1992, with Alberto Burquez; 26 Nov 1994 and 3-4

Jan 1995, with Silke Schneider; 15 Feb 1995, with Michael Wilson; 6 Jan

1995, with Silke Schneider, Gil Gillenwater, and Esther Tittle.

Bonnie Fine, 12 Mar 1977.

Margaret (Peg) Gallagher, 17 Oct 1981 (ASU); 15 May 1982, see entry for

Parfitt.

Howard S. Gentry, 29 Mar 1963, Cerro 4-5 mi N of Bahia San Carlos,

arid palm canyon with volcanic rocks, with Juan Arguelles; 17 Jun 1975,

ca. 5 mi N of Bahia San Carlos, with Rodney Engard.

Paul S. Martin, 24 Dec 1970; 12 Mar 1977.

Edward Palmer, 12 Oct 1897. Some of his specimens merely labeled

“Guaymas” are actually from the canyon, although a few say “Nacapuly,

15 miles west of Guaymas” (see Asclepias leptopus and Passiflora

mexicana). McVaugh (1956) reports that nos. 255-260 in 1897 are from

“Nacapuly.” Palmer’s often relatively detailed notes rarely accompanied

his specimens into the the herbaria to which they were distributed

(McVaugh 1956:vii). Also see species account for Abutilon abutiloides.

Bruce Parfitt, 15 May 1982 (ASU), with Martha Burgess, Sylvia Forbes,

Margaret L. Gallagher, Carol Starr, Gregg Starr, and George Yatskievych.

Arthur M. Phillips, II, and Barbara G. Phillips, 9 Mar 1975, with Fred M.

Wiseman; 26 Oct 1975, with Lee Karpiscak, Martin Karpiscak, Raymond

M. Turner, Fred M. Wiseman, Martha Ames Wiseman, and Wally

Woolfenden.

Ana Lilia Reina-Guererro, 18 Feb 1995, with Jesus Sanchez-Escalante,

Oscar Gutierrez, Telma S. Fuentes, and L. Morales.

Gregg Starr, 17 Oct 1981, with Martha Ames Burgess, Margaret

Gallagher, Robert Perrill, and Vicki Phelps; 15 May 1982, see entry for

Parfitt; 28 Dec 1982, with Carol Starr, Tom Van Devender, and Florence

H. Nishida; 1 Jan 1984, with Carol Starr and Laurence J. Toolin.

Victor Steinmann, 13 Mar 1992, with Cele Smith and Jenny Davidson; 15

Aug 1992, with Cele Smith.

Laurence J. Toolin, 1 Jan 1984, see entry for Starr.

Raymond M. Turner, 4 Oct 1979, with Paul S. Martin.

Thomas Van Devender, 28 Apr 1982 and 28 Dec 1982, see entry for Starr;

23 Apr 1984, with Robert Perrill, Jacqueline Soule, and Rebecca K. Van

Devender.

Peter Warren, 18 Aug 1975, with D. E. Goldberg.

John F. Weins, 17 Jan 1993, with S. Horley.

Martha Ames Wiseman, see Martha Ames.

George Yatskievych, 15 May 1982, see entry for Parfitt.

but natural habitats in nearby rugged mountains remain virtually intact.

Even in the 1960s cattle grazing, wanton burning, and woodcutting in

the canyon had taken their toll (Felger 1966). Until the late 1980s,

however, the canyon remained only minimally altered from my first

visit on that hot summer afternoon in the 1960s when the population of

the entire state of Sonora was less than half of what it is today. The road

from San Carlos to Nacapule was a rough, rock-filled dirt track until

the 1990s. At that time a road had been pushed up the canyon, parts of

the canyon floor’s forest cleared, decorative rock extracted from the

slopes by use of dynamite, and some of the trees smashed. Substantial

portions of the understory vegetation in the lower canyon has disap-

peared. Increased tourism is also affecting the vegetation, resulting in

trash, minor vandalism, and trampling of fragile wetland vegetation.

The Nacapule region is at the southern margin of a 50,000-ha

reserve known as Cajon del Diablo, established “on paper” in 1937

as a hunting reserve. This “reserve” is not strictly delimited and has

not received formal management, although there are efforts to turn it

into an actual managed reserve, called Caj6n del Diablo y Cafion de

Nacapule (Burquez and Martinez-Yrizar 1997).

Canon de Nacapule is a small and vulnerable place. Enough of

the canyon biota remains that its recovery could be rapid if protected.

The land is owned cooperatively by an ejido and is a popular place

for hiking and ecotourism. I suggest that a nongovernmental conser-

vation organization in Mexico make arrangements with the ejido to

eliminate mining, the road, vehicles, and cattle in the canyon, and to

limit general access to the one major established trail. Modest en-

trance fees from a controlled number of visitors would generate

higher income than is presently being earned. The canyon and the

rugged surrounding mountain areas are not suitable for other devel-

opment. Access to the canyon is from only one easily controlled

place, so effective management is feasible. This special place de-

serves vigorous protection.

ANNOTATED CATALOG OF THE VASCULAR FLORA

The flora is presented alphabetically by family, genus, and spe-

cies with the ferns and fern relatives listed first, followed by the di-

cotyledons and then the monocotyledons. Plants not native to the

region are indicated with an asterisk (*). Nomenclature used here

results from my studies of the regional flora. Selected synonyms are

given in brackets. Some common names are provided, with the local

Spanish name(s) first, followed by the English name, and in a few

cases Yoeme (Yaqui) names (the last are from a manuscript Felipe

Molina and I are preparing). Measurements for length or height pre-

cede those for width, and the terms length, long, or height are omitted

unless needed to avoid confusion. Flowering times are expressed by

the season or months of probable or known flowering. In many cases

flowering times or seasons vary greatly from year to year, and one

can expect variation greater than what is presented here. Flower color

refers to the dominant or most conspicuous color of the flower.

Three general kinds of ephemerals (desert annuals that complete

their life cycle within a single season) are distinguished: (1) Winter—

spring ephemerals grow during the cooler seasons and may flower

during late fall, winter, and/or spring. (2) Hot-weather or summer

ephemerals usually germinate with the first substantial summer thun-

derstorms. Some may also grow with early fall rains (such as hurri-

cane-fringe storms) while the soil and air temperatures are still high,

allowing quick maturity. (3) Nonseasonal ephemerals grow with suf-

ficient soil moisture at any time of the year.

Specimens cited are deposited at the University of Arizona, Tuc-

son (ARIZ), unless otherwise indicated. When more than one collec-

tor is listed on a label, usually only the first collector is given. My

specimens are identified by “F” plus the collection number. When no

collection number is given on the label, the specimen is identified by

the date of collection. I have seen all specimens unless otherwise

The Flora of Canon de Nacapule: A Desert-Bounded Tropical Canyon near Guaymas, Sonora, Mexico 7

noted. Only selected specimens are cited, and in many cases there are

additional specimens, especially at ARIZ. At least in the case of my

collections an additional set is at the Instituto de Biologia,

Universidad Autonoma de México, Mexico City (MEXU) or, for

many of my earlier collections, the Escuela Nacional de Ciencias

Biologicas, Instituto Politécnico Nacional, Mexico City (ENCB),

with duplicates variously distributed primarily to the California

Academy of Sciences, San Francisco (CAS), Rancho Santa Ana

Botanic Garden, Claremont, California (RSA), the San Diego Natu-

ral History Museum (SD), the University of Texas, Austin (TEX),

and the University of California, Berkeley (UC).

KEY TO THE MAJOR PLANT GROUPS AND FAMILIES

1. Plants spore-bearing, without flowers or seeds; leaves those of typical ferns, or nearly leafless and stems dichotomously branched,

RSIIGLO TOUS SEXO) CIT echooteesconobcorttoacieadouechsone REaacone aecacooc Mo eonSUCaETCecauastaG

5088011949006013550553230044055600006080od90590co CHOC COEKOGAOcICbAcICHNAdD PTERIDOPHYTES

Laguested sassevuseenetieeassissvestiestterees sores torent FLOWERING PLANTS:

2. Agaves, aquatic plants, cattails, grasses, sedges, sedgelike plants, or palMs ............:cccceeeeeeeee MONOCOTYLEDONS (page 38)

Du Wotheniplantsynotiasia bOVGressscsecercsetectecsecstcs secreertees eee:

PTERIDOPHYTES—FERNS AND FERN RELATIVES

1. Plants not fernlike, with erect, dichotomously branched green

IG ANTES (GIEITING secnconccococcnotacdoadocobactiscaasoodacasbadcuosseuooasoon Psilotaceae

1’ Ferns; stemless but with brown to blackish rhizomes, the

leavesiwellidevclopedieesceeeeseeesnnteeee rere Pteridaceae

PSILOTACEAE—Whisk-fern Family

Psilotum nudum P. Beauv. A single colony “with about a dozen

stems two to three inches high . . . at an alga-covered seep on the

canyon wall in the shade of palms” (Boutin 1971). Spring, 1970,

Boutin 3814 (Huntington Botanical Garden); propagations from

this collection cultivated at the Huntington Botanical Garden

(HNT no. 25061) and specimen of a portion of “plant cultivated at

Huntington Library Botanic Garden” (ARIZ 260328).

Although the plants were small, apparently stunted by the rela-

tively dry conditions, in cultivation they reached 15-17 cm, within

the usual size range for the species. The Psilotuwm colony was found

in the upper part of the canyon. I could not relocate it in spite of

precise information provided by Myron Kimnach, one of the original

collectors. Perhaps this stunted colony succumbed to drought. There

are no other records for this moisture-loving plant within the Sonoran

Desert. The nearest known populations are in oak woodland in Sy-

camore Canyon in Santa Cruz County, southern Arizona (Toolin et

al. 1979), and in pine forest on the Sierra Saguaribo in southeastern

Sonora (Gentry 1942).

PTERIDACEAE—Brake Fern Family

The four ferns have leaves that curl up tightly during dry periods

and expand during moist conditions to reveal green surfaces.

sebteccdstdocce St SELLA AUPE See Ee Set eR DICOTYLEDONS

1. Leaves once-pinnate, the upper surfaces of leaf segments with

often deciduous stellate-pectinate scales (star-shaped and

COMDINKE) oe ie seta esses eter ne aaceacee Astrolepis sinuata

1’ Leaves 2- or 3-times pinnate, without stellate or pectinate

scales, the upper surfaces of leaf segments mostly glabrous.

2. Leaf segments green on both surfaces, edged with a nearly

continuous margin Of SOT1 ....... eee Cheilanthes lozanti

2' Leaf segments brownish or whitish below, green above, the

sori not forming a continuous margin.

3. Leaves <12 cm, divided into numerous minute segments,

the lower surfaces green with brown SOM ..........:.:eeceeee

Seley ete sabes dos atcd aide ee a at oet eae tenon are eae Cheilanthes pringlei

3' Leaves 20+ cm, the segments not numerous and minute,

the lower surfaces white .............2.. Notholaena lemmonii

Astrolepis sinuata (Lag. ex Sw.) D.M. Benham & M.D. Windham

subsp. sinuata [Notholaena sinuata (Lag. ex Sw.) Kaulf.]. Wavy

star-fern. Crevices in rock ledge on north-facing canyon wall;

rare. F 92-1030.

Cheilanthes lozanii (Maxon) R. Tryon var. seemannii (Hook.)

Mickel & Beitel. [Pellaea seemannii Hook.]. Leaves mostly 20-30

cm, pale green, the sori golden-brown. Among rocks in canyon

bottom and on north-facing slopes. F 84-136.

Cheilanthes pringlei Davenp. Diminutive ferns with creeping

rhizomes. Shaded north-facing rock slopes; rhizomes often in

moss and humus overlying rock surfaces. F 84-135, 85-1186.

Notholaena lemmonii D.C. Eaton. Leaves at least twice as long as

wide. Among rocks on north-facing slopes. F 84-/00; Gallagher

275.

FLOWERING PLANTS

DICOTYLEDONS

1. Plants parasitic: KEY 1.

1’ Plants not parasitic.

2. Plants succulent but not parasitic: KEY 2

2’ Plants not succulent.

3. Vines: KEY 3.

3’ Not vines.

4. Composites: individual flowers small and borne in a head often resembling a single large flower, the head surrounded by a

series of somewhat sepal-like bracts forming an involucre, the heads often sunflower- or daisylike, with a central group of

tubular disk flowers often surrounded by a ring of ray flowers, or the heads of disk flowers only, or dandelionlike and all

flowers with a strap-shaped corolla; ovary inferior, the fruit a cypsela (“achene’’), topped by scales or bristles forming the

pappus, or the pappus sometimes none. ........0..0 eects

4' Not composites.

5. Leaves compound. KEY 4

5' Leaves simple.

SR STEboi ache dheateazces teat ten ae tes Fadia oeauasicatente nace veessoees penemnee eee Asteraceae

8 Richard S. Felger

eaves whorled or appearing whorled: KEY 5

eaves alternate or opposite.

. Leaves opposite: KEY 6

7' Leaves alternate: KEY 7

6. L

Olu

KEY 1. PARASITIC PLANTS

1. Stems vining, threadlike, and orange; flowers white, the perianth consisting of a well-defined calyx and corolla ..........0....:cccccccceseeees

| CEES ESE E ESC ERE EE CCE EE EERE Cae eeec EPEC aocaG ccedce noc cE Bceadheertagd sneroesiotancine io doncacriobasieocaaonatacaleaeadtck Sinn soocsudracnanancosacea Convolvulaceae (Cuscuta)

1' Stems not vining, not threadlike, and not orange; flowers cream-colored, yellow, or red, the perianth of calyx only (corolla none).

2. Leaves more than twice as long as wide; flowers cream-colored OF Pe .......ccccccccsceseseseseseseesesessssesesesececsesssecsesesececsesesees Loranthaceae

2' Leaves about as half to fully as wide as long; flowers small, yellOW ...........:..:cesccscceceeceeceeseeeeeeceseseescesecacesecsecssenseeseesseaseae Viscaceae

KEY 2. SUCCULENT PLANTS

IMCactitstemsiwithareolesjibearingyaiclustenmolyspinespesnceee-eceesescetceoseee tee Cactaceae

1’ Not-cacti; without areoles, without spines, or the stem tips spinescent.

2. Plants herbaceous, mostly <50 cm; sap not milky; stems leafy.

3. Leaves deeply dissected or lobed, often somewhat glaucous; flowers pale pink, in dense, many-flowered heads on long

PEAUNCL ES oir ress ted cevmes aces cael carc eet isa eetase nes Pouce scneat couse idan ize'ecasbgeney sevsde cuter savenucen suusteeiceee eek teestcy on eccenes Asteraceae (Hofmeisteria)

3' Leaves not dissected or lobed, the margins entire, not glaucous; flowers yellow, orange, or deep pink to purple, in open, loose

panicles or solitary and sessile or short-pediceled in leaf axils «0.00.0... eeeeeeeeee Portulacaceae

2' Plants shrubby or semi-shrubby, mostly >50 cm; sap milky; leaves few and reduced, filiform or narrowly linear.

4. Stems waxy, grayish white, wandlike, quite flexible, not spinescent-tipped. Asclepiadaceae (in part)

4eStems green, rather tinm! spimesCent-tipped yer c..sces.sesu-encuses-snseestenseeeece soon eee eeeeee ee Euphorbiaceae (Euphorbia ceroderma)

KEY 3. VINES

1. Plants with stinging hairs; leaves 1.5-4 cm; flowers unisexual, small and inconspicuous. .............0::::eceseeeee Euphorbiaceae (Tragia)

1’ Plants glabrous with nonstinging hairs; flowers bisexual (except Dalechampia)

2. Plants with tendrils.

3. Leaves pinnately or bipinnately COMPOUNA .......... eee eeseeeseenceneeecetecesceneeneesterseesersceeeees Sapindaceae (Cardiospermum, Serjania)

3' Leaves simple although sometimes deeply lobed.

4. Flowers and their bracts pink; tendrils at ends of flowering branches .............:c:ccecceseeseeseerseeseeseeseens Polygonaceae (Antigonon)

4' Flowers white or white with blue or purple; tendrils at bases of inflorescences or leaves.

5. Tendrils on inflorescence peduncles; leaves shallowly toothed but not lobed; flowers <0.5 cm in diameter; fruits dry,

WOTREOEN NU oIG esr enetecrercenocee eccaAtr Seta ecco or coccpeicorecctoconchsteectadaacec ce SacaanteconocLe oo ccdacuc dona ccaseeoedesdeLessoasee Rhamnaceae (Gouania)

5’ Tendrils at leaf bases; leaves shallowly to deeply lobed and toothed or not; flowers at least 1 cm in diameter; fruits fleshy,

not winged.

OMS tIPULESIMONES Wil OW.ETSHUIMISE XU alllene wees areca een eee ee Cucurbitaceae

6' Stipules present; flowers bisexual Passifloraceae

2' Plants without tendrils.

7. Ovary inferior; perianth 3.5-5 cm, consisting of a single, bilateral segment, toothlike above and funnel-like below; leaves

amo WeShapedsthelsappn © toni kay ae eeeeeeee eects eee eee Aristolochiaceae

7' Ovary superior or inferior; perianth not as above, with sepals and petals; leaves not arrow-shaped, or if so then the sap milky.

8. Leaves compound or divided nearly to the base.

9. Flowers bilaterally symmetric, pealike, pink, purplish, or yellow. Fabaceae (Nissolia, Phaseolus, Macroptilium, Rhynchosia)

9' Flowers radial, not pealike, various colors.

10. Leaves palmately parted, the leaf segments with entire margins; flowers bisexual. Convolvulaceae (Ipomoea leptotoma)

10’ Leaves pinnately parted or divided, the leaf segments with toothed margins; flowers UNISeXUAL ............eeeeeeeeeseeseeeeeeeeeee

Seas su eit sativus cwaetceey ete scoesaaesciectves nee cesh eerie or cia de oaccts toes ee RR ee OR Euphorbiaceae (Dalechampia)

8’ Leaves simple.

DCAM UALS ences. cccentse cea Seeivecssceeeectan eee teeseece eusecoesee sede Teate tra eo eee ey ie om sa ee Convolvulaceae (Jpomoea in part)

11’ Perennials.

WDMILeavestalterm ate eee Poses oss sscscsc sacs aeecave sbscec en technetium Soe oe ESET oe a eee Menispermaceae

12' Leaves opposite.

13. Sap milky; petals white, cream, greenish, or white and maroon; fruits not Winged .......... eee eee eeeeeeeeeseeeeseeseeeeeeneeseeres

KEY 4. LEAVES COMPOUND

1. Leaves opposite; summer ephemerals or hardwood shrubs and small trees ...........:.:ccesseceseeseeeseseeseereeeseseeseesenseeeseesees Zy gophyllaceae

1’ Leaves alternate; herbs to trees.

2eomallkannualtherbssleayes;palmately (comp ouind essere esate rears eee eee eee Capparaceae (Cleome)

2' Herbs to trees; leaves pinnately or bipinnately compound.

3. Leaflet margins crenate to toothed; leaves glandular punctate, with a citruslike odor when crushed ..... Rutaceae (Zanthoxylum)

3' Leaflet margins entire or sometimes shallowly toothed; leaves not glandular punctate, not smelling like citrus.

The Flora of Canon de Nacapule: A Desert-Bounded Tropical Canyon near Guaymas, Sonora, Mexico 9

4. Plants armed or unarmed; leaves with pulvini at bases of petioles and/or leaflet stalks (pulvini are swollen, often dark areas

that swell or contract to move the leaves and/or leaflets); stipules often well developed and persistent; leafstalks often with

pLrominentmnectanyscland(S) sir tsvone=stoMMany—-SCCCEAtsesccssesrescencnseareacsnenssrcccstsceatsszssecsvan-sosapssennezesnasarenspeostassisnerccstes Fabaceae

4' Plants not armed; leaves without pulvini or leafstalk glands; stipules none; fruits one-seeded

5. Leaflets <1 cm wide; fruits dehiscent with a red or yellow aril, 8 MM................:ecccescceeceecceerceecceeceees Burseraceae (Bursera)

5' Leaflets 2—5 cm wide; fruits indehiscent, without an aril, at least 12 mm. .. Sapindaceae (Sapindus)

KEY 5. LEAVES WHORLED OR APPEARING WHORLED

1. Trees and shrubs.

2aStemsiunanmediand (flexible silo wershuniS@Xualtescescsecsscsentecersssseresctsccuvsuesesasssneussassvssasveceussqceness Euphorbiaceae (Jatropha cuneata)

2' Stems armed and rigid; flowers bisexual.

3. Leaf clusters (short shoots) often subtended by a rigid spine; flowers at least 1.5 cm, tubular, and red ................ Fouquieriaceae

3' Twigs spinescent only at tips; flowers <] cm long or wide, saucer shaped, and yellow-green ...........0::c eee Rhamnaceae

1’ Plants herbaceous.

4. Flowers sessile in dense spikes, the peduncles and spikes clothed in firm, overlapping bracts with pointed tips .........0...0.:::cceeee

ated racemes, without bracts as above.

eled, in

4’ Flowers pedic small clusters or dense to elong

Seeman thiradialsawithisepal sibutmo petal sjececeseeseeetescectcereeccenecr cere cuce sees teenetsa eee seen aetna a Molluginaceae

S/Renanthibilateralswaithisepal srandlipetal Sieseescsscssecstecevsessssesscescceseeceswneseee ees Scrophulariaceae (Antirrhinum, Linaria, Stemodia)

KEY 6. LEAVES SIMPLE AND OPPOSITE

1. Stems square in cross section; leaf margins serrated to toothed.

2aWeaves oftenswhitishs plants wathibranchedwihite) haitsyccsccccc-cerescesceesces-sosenceseesse eoeceereeneeeneteetersos ence tenet oe oesce tence Lamiaceae

Dulbeavesyereenishssplantsawsthysimpleyh airspeesss-nsccsesescsscssssncnsceztescosscnsss=cescesertacesertesnctreceeuataastcctsscet titans ensensenns sa deeateae nc Verbenaceae

1’ Stems terete; leaves entire.

3. Trees or woody shrubs usually >1 m.

45 Plantsrarmedhwath—4ispinesime ari twil SA tips|ssecceesea-oeee nesses nee sec res ncaa necro ecrteence seca ccenaase cee eeaees neem Rubiaceae (Randia)

4’ Plants unarmed.

5. Leaves opposite or fascicled, linear-oblong to narrowly elliptic, <1 cm wide, markedly glandular-punctate .......0...0..0..e ee

SERS pect he BAR ce ee ra arlene RA eC as 5, ns enn Saleh aR or ail ae ee Lapa eH Uh ts no Oleaceae (Forestiera)

5’ Leaves all opposite, broadly elliptic to ovate, >1 cm wide, not glandular-punctate.

6. Small trees or treelike shrubs usually taller than wide, mostly with a single, well-formed trunk and corky-ridged bark;

leaves relatively thin and not at all leathery; flowers bisexual; capsules many-seeded ..................00: Rubiaceae (Hintonia)

6’ Much-branched, trunkless shrubs as wide or wider than tall, the bark smooth: leaves leathery; flowers unisexual; capsules

ONE=-OTtWO=SECME A. wessc elec eecectesssecleees hes ces tees desc ost easvac vas vds soaatuaks Beadaaauves cost zat tio leete A nes u tee esis sees Teese tea ee ets Simmondsiaceae

3’ Plants herbaceous, if somewhat woody then mostly <1 m and generally woody only near the base.

7. Herbage or fruits glandular-sticky; flowers pink, white, or dull greenish yellow ..............ccccceeeeceeeecesceeeeeeseeeeeeeeee Nyctaginaceae

7’ Plants glandular or not but not sticky; flowers of various colors.

8. Herbage woolly-pubescent, at least when young; flowers small and inconspicuous. Amaranthaceae (Froelichia, Tidestromia)

8’ Herbage glabrous or pubescent but not woolly; flowers conspicuous.

9. Corollas bilateral.

10. Perennials; fruits several-seeded, elastically dehiscent capsules ...............0ccceceeeeeeeeeee Acanthaceae (except Elytraria)

10’ Annuals; fruits many-seeded capsules, not elastically dehiscent .............0.20..4. Scrophulariaceae (Antirrhinum, Linaria)

9' Corollas radial.

11. Pubescence of simple hairs or plants nearly glabrous; fruits dehiscent, paired, and slender. Apocynaceae (Haplophyton)

11’ Pubescence of two-armed hairs or plants nearly glabrous; fruits indehiscent, not paired, and not slender .......................

Pa 20. 3 ie Se KARE se IRON Ne Rr ae I, SSSR SNS I I A Pe eted ky SEPT ee OS ERE TE Malpighiaceae (Callaeum, Galphimia)

KEY 7. LEAVES SIMPLE AND ALTERNATE

1. Woody shrubs and trees, usually >1 m.

2. Leaves or stems armed.

Sulbeavesispine=tipped-iplantiothenwiSevun armed eave seaee ese eet ee eee eee ee en cee eee Dee eaneian ane sec eee Roe Nestea rece Theophrastaceae

3’ Leaves not spine-tipped; the twigs, nodes, and/or leaves variously armed.

Al Vel Coy nese LV EWES TREE 9) OZ, [DUET cer creconceecodceceacececenccoaceec0050635555640060060600050 055855000060 085062 50005 505005005 E OSD STO RIB EOSSOOEDEEED Krameriaceae

4' Flowers radial; fruit not a spiny bur.

5. Leaf veins not readily evident.

6. Trees or large shrubs with a well-formed trunk, the bark light-colored, checkered to furrowed; leaves not fleshy.

BEE ae ECE MCE CODE PSC CELE OPER eee SCRE PRES CE ocd ER SOaS cee RO REC rcciancan coer pac oe ess ca cebo cae ERODE apo sodacoocboesaGeb Sapotaceae

6' Shrubs lacking a well-formed trunk, the bark mostly smooth; leaves often semi-fleshy.

7. Sepals 4, petals none; fruits whitish, drying blackish, one-seeded .............::.:tee Phytolaccaceae (Phaulothamnus)

7' Calyx and corolla present, each 4- or 5-lobed; fruits orange or red-orange, multiple-seeded ....... Solanaceae (Lycium)

5’ Leaves with prominent veins (at least the midrib prominent). :

toh, TETRIS Sill) GSU. NENTS: cccooaseaccoocosocnoceoccaccéccecccoscoscorseeaowopse997e90060002960046640Nea¢ncon.OsoUSosaCeaReNEGNNAROCHOOIGI0 Solanaceae (Solanum)

8’ Plants glabrous or the hairs not stellate.

10 Richard S. Felger

@)IEGENIES GLP ID O1NS chcsoscocaccocuosoesoco0uocsec06006c6055e000q0600300s6ed89600580895.ed0d06oo cba cocebosaSobpbSasocés90060660d0000800050500003800000600400000005 Ulmaceae

9' Leaves not scabrous.

10. Long-shoot branches with a rigid spine at many or all nodes; flowers tubular, red, at least 1.5 cm. Fouquieriaceae

10' Twigs spinescent only at tips; flowers saucer-shaped, yellow-green, <1.0 CM 0.0... Rhamnaceae

2' Plants unarmed.

11. Sap milky.

(1D), TESAUTTIMENREATINS (KOLO,TT EYE ccecccccocsco0c035e00%0c006600s06004000000005020002905560200460N600s90290nda099G0do0edccECcdncceccanccodeonee000090 Euphorbiaceae (Sebastiania)

12’ Leaf margins entire.

13. Stipules minute or not apparent, not enclosing terminal growth buds; flowers small but conspicuous, fragrant, and white,

Siilida) CPI yi< TVG: (07100) UE) ccecc00cces0c0cocsocoee000000000%628e263060085680010s0509000000000350000000s50007570s0904Tas990GT=sREaTETqTIATOTATON Apocynaceae (Vallesia)

13’ Stipules conspicuous, the growth bud enclosed by a pair of elongated bractlike stipules falling away as the new leaf

expands, the fallen stipules leaving a ringlike scar on the twig; flowers not fragrant, inconspicuous and minute, enciosed

HD AU ile, (Hates jOLeLOTET NH OL TOVOXE EMAILS ccocotseccacasesecnosesececeonacunnoq9c000907000ed0¢)c07070G00caqza9ocecaqaGzabEaECoseccesoTEeadocpoTacoecoETASESACeNSasICN Moraceae

11’ Sap not milky.

- 14. Leaf blades narrow, more than twice as long as wide.

15. Trees with a thick, single trunk; leaf margins conspicuously inrolled ..............0:cceeeeeees Capparaceae (Forchhammeria)

15’ Shrubs; leaf margins not inrolled.

N6sklowersibilateralsainui teas piniys WU ieee cecesesseeeecce erate stress cecea nse nrutenaesneersreseonen terete matt neneareerer eer enees Krameriaceae

16’ Flowers radial; fruit not a bur.

17. Herbage not sticky-viscid; stems thick and semi-succulent ..

17' Herbage, especially when young, sticky-viscid; stems slender, not

14’ Leaf blades broader, less than twice as long as wide to wider than long.

18. Flowers unisexual, generally inconspicuous.

19. Shrubs; leaves not scabrous; flowers all unisexual; fruits of two- or three-seeded Capsules .............ccccccccceseteeeeeeteeeeeees

SEALE CO LEESC CSO BOSCO GOOE SER SOS HCE eos ooCOE CECE SESE REC EES peepee oo op eee eacood Euphorbiaceae (Acalypha, Adelia, Croton, Jatropha)

19’ Trees with a well-formed trunk; leaves scabrous; flowers both unisexual and bisexual, often on the same branch; fruits

OVMOSESO TEC | CITY SYS ccoocoocensenc000300709200072600005805000355525980703805068050030000000000200c05660C Sd odCLEsacTaCTSdOGTEGEOCEE Ulmaceae (Celtis reticulata)

18’ Flowers bisexual, small and inconspicuous to large and showy.

20. Leaves serrate-toothed.

.... Euphorbiaceae (Jatropha cuneata)

SUCCULEN tes eesste reese: Sapindaceae (Dodonaea)

21. Hairs stellate; flowers maroon) or rose-lavenden ............--..-..-+ss+sessescescoesseeeseeseeeeseseeee Sterculiaceae (Ayenia, Melochia)

21' Hairs simple; flowers yellow-green or white.

22. Hairs coarse, firm; flowers >2 cm wide, White .............:eceseesceseseeseseeseeeeeeeseeseaeens Boraginaceae (Cordia parvifolia)

22' Hairs slender, soft; flowers <1 cm wide, yellow-green Rhamnaceae (Colubrina californica)

20' Leaves entire.

23. Leaf blades nearly orbicular with a rounded or blunt apex; stipules forming a tubular cap enclosing the developing

bud and later clasping and encircling the Stem ............ccecescsceeseeseeeeeesesecseeseeseteeseeecesseneeaes Polygonaceae (Coccoloba)

23' Leaf blades longer than wide, or if nearly as wide as long then the apex pointed; stipules none or not as above, not

sheathing the stem.

24. Plants glabrous (including new growth).

25. Twigs brittle, the wood not hard; leaves somewhat fleshy and semi-succulent; flowers white; fruits red ............

#665 o000eF00q 00000 > -DEESOECUECEIDED-OCOIC ER SCRICOCESERE ADEE ES CEC OCOE EEE ESE 0500S COR O5GDDGI IGG aGDOAEESDSONSEIED Phytolaccaceae (Stegnosperma)

25' Twigs of flexible, nonbrittle hardwood; leaves thin, not at all succulent; flowers yellow-green; fruits brown ....

... Rhamnaceae (Colubrina glabra)

and/or calyces.

26. Plants scabrous or with two-armed hairs.

27. Shrubs; pubescence of two-armed hairs, not scabrous; flowers bright yellow, showy, >10 mm wide ..............

Ber boat edoesace coon ce dee ao acooco oe coer cece ace cco sear Seca ooo a aeoaaaaascasoobocoa soe Doar odasccacoecuEcocLocd Malpighiaceae (Echinopterys)

27' Trees: leaves scabrous, the hairs simple (not two-armed); flowers yellow-green or green, inconspicuous, <6

mm wide ... 3 Ulmaceae (Celtis reticulata)

26' Pubescence of simple soft hairs.

28. Leaves mostly <5 cm, the blades soft, not firm; individual flowers <1 cm wide or long, inconspicuous, the

flowers and fruits enveloped in tufts Of White hairs .............ccccccessesseseseeeseeeeeeteeseeetneees Amaranthaceae (/resine)

28' Leaves mostly >5 cm, the blades rather firm; flowers at least 3 cm wide, showy, not enveloped in hairs........

.. Boraginaceae (Cordia sonorae)

1’ Annual or perennial herbs, not woody or scarcely woody below, or if somewhat woody then generally <1 m.

29. Herbage and/or fruits spiny.

30) Herbage! and fruits! spiny; stamens) MUMELOUS) «..2.2..2..22...crsccse-oveoseosseonesneoneoneeeneseesaceneeacenscurtertcrtecceccerccsrertesnssnsvcssusvaees Papaveraceae

30' Herbage unarmed, the fruits spiny; stamens 5.

31. Shrubs; fruits ca. 1-1.5 cm in diameter ...

31’ Annual herbs; fruits >3 cm in diameter ...

29' Herbage and fruits unarmed.

32. Flowers unisexual; fruits three-seeded Capsules ............:ccceceseeeeceeceseesceseessesecseeeeeeeeeeeneeneees Euphorbiaceae (Ditaxis, Euphorbia)

32' Flowers unisexual or bisexual; fruits various but not three-seeded capsules.

33. Pubescence of stellate or dendritic hairs.

34. Hairs dendritic, the herbage, calyces and fruits sticking like Velcro; stamens separate ...

34' Hairs stellate, the herbage, etc., not sticking; stamen filaments united, at least basally.

.. Krameriaceae

... Solanaceae (Datura)

Loasaceae

The Flora of Canon de Nacapule: A Desert-Bounded Tropical Canyon near Guaymas, Sonora, Mexico lI

35. Fertile stamens many, the filam ents united for at least half their length. ..............csccesscesecsscesscesseeeceessesecensenes Malvaceae

35’ Fertile stamens 5 (Ayenia also has 5 staminodes), the filaments united only at base. oo... cceeeeeeseeereeee Sterculiaceae

33' Pubescence of simple hairs or plants glabrous.

36. Perianth 4-merous (calyx 4-lobed, or sepals 4; corolla, if present, 4-lobed or petals 4).

37. Calyx present, the corolla absent; stamens 4; fruits one-seeded.

38. Bushy summer-flowering perennials; flowers bisexual, small but conspicuous, white, in slender terminal and

axillary racemes; fruits red, fleshy ......... cece

cb daesaccar teorcaes rest teeicnsstvascrer toe Contre tren Cssee eters Phytolaccaceae (Rivina)

38' Winter—spring annuals; flowers bisexual and unisexual in same cluster, inconspicuous, dull green or brown, in

dense axillary clusters; fruits brown, dry. ....

. Urticaceae

37' Calyx and corolla present; stamens 6 or 8; fruits multiple-seeded.

S9ONCool-seasonannualswOVahysSUPeLlOUsSUATMENS|Onreeescerssssecceesceccecescesctectsuccures sautaere cesmarechetne stew eeatese anaes Brassicaceae

39' Warm-weather annuals or perennials; ovary inferior; stamens 8. .............cceesecseecesseceeeeseeseneeseneeseneeseeeeaseee Onagraceae

36' Perianth various but not 4-merous, often 5-merous.

40. Annuals; flowers small and inconspicuous; sepals green or straw-colored, the petals none; fruits one-seeded.

41. Flowers unisexual; fruit a circumscissile Capsule. ............:..:ceccsscsssessessessessensenseessereensense Amaranthaceae (Amaranthus)

41' Flowers bisexual; petals none, fruit an achene. ..

2st eae ees Chenopodiaceae (Chenopodium)

40' Annuals or perennials; flowers small or not, with sepals and petals, variously colored; fruits one- to many-seeded.

42. Flowers bilateral.

43. Leaves all alternate, the margins sparsely toothed; flowers whitish; fruits 3-seeded «0.0... ce eee Violaceae

43' Leaves alternate and some sometimes also whorled or opposite, the margins entire; flowers pink, blue, or purple;

fruits with 4 or more seeds.

44. Flowers sessile in dense spikes, the peduncles and spikes clothed in overlapping bracts with pointed tips .........

agunebs cea ites ce seve seeenees deyets cute vurendvervinezseesirevstes Acanthaceae (Elytraria)

44' Flowers pediceled in dense to elongated racemes, without Overlapping bracts .............cccceeeseeeceeeeeeeseeseeseeeeteeeees

42' Flowers radial.

Scrophulariaceae (Antirrhinum, Linaria)

45. Inflorescences and calyx with sticky, stalked glands; flowers white, small but showy; seeds | .... Plumbaginaceae

45’ Plants glandular or not, but not sticky; flowers white or variously colored; seeds more than 2, generally 4 or more.

46. Flowers bright yellow; fruits 7-10 cm, paired, very slender .........0...ceeeeeeee Apocynaceae (Haplophyton)

46' Flowers yellow or not; fruits to ca. | cm, not paired and not slender.

47. Inflorescence branches helicoid.

ARS), ILC ENVES CAELHITS asoocaccasoocacaneesq0000d006005000360

48’ Leaves pinnately lobed or toothed.......

SSPEARS MIE 8 SA ee eer OO ere ne Rana teen Boraginaceae

BE ECE Oc PASSER EE CEH obo sastoean coneAsonoarCENCeEON Hydrophyllaceae (Phacelia)

47' Inflorescence branches straight, not helicoid.

49. Stamens many, the filaments united into a column or tube; style branches more than 5 ............. Malvaceae

49' Stamens 5, the filaments separate from each other; style branches 4 or fewer.

SOPStyleundivideds thejsti oma S-Clelt censecesssscescessenescosscnconcassessnsrestesstornscese eran teeeaee eee Polemoniaceae

50' Styles and stigmas unbranched, or styles 2 and each two-branched.

51. Styles 2, each with a two-lobed stigma; seeds 4 or fewer «0.0.0... Convolvulaceae (Evolvulus)

51’ Styles and stigmas unbranched; seeds many per fruit ...... Solanaceae (Nicotiana, Physalis, Solanum)

ACANTHACEAE—Acanthus Family

1. Leaves alternate or whorled; flower clusters on long scaly

SLOMISE eetacccee ta seesds Sotsceteacs casts vavauvuscstescceutdocesodtesyseceeseess Elytraria

1’ Leaves opposite; inflorescences not on scaly stems.

2. Shrubs or dense mound-shaped bushes.

3. Leaves conspicuously glandular-sticky; corollas lavender,

large and showy, about as wide as long.................. Ruellia

3' Leaves not glandular-sticky; corollas not lavender, longer

than wide.

4. Corollas rose-pink; fertile stamens 4......... Holographis

4' Corollas red-orange or red; fertile stamens 2. ................

asteiu erottseewevessitees Justicia (J. californica, J. candicans)

2' Perennial herbs.

5. Floral bracts large, 4-ranked, the flowers in dense spikes;

CEU GEIOLDEG ls ceccaccococscenaeatooetaconcecadcdoondene560500 Tetramerium

5' Floral bracts not noticeably large, not 4-ranked, the

flowers not in dense spikes; calyx 4- or 5-lobed.

6. Calyx 4-lobed; flowers lavender; capsules glandular.

Leet ce he abet ese ogee eats Maree ENS, Justicia (J. sonorae)

6' Calyx 5-lobed; flowers white or yellow with purplish

markings; capsules not glandular.

7. Capsules narrowly club-shaped, gradually tapered

below; corollas <1 cm wide... ... Aphanosperma

7' Capsules broadly club-shaped, abruptly narrowed

below to a claw; corollas ca. 1.5 cm wide.

anisddbtsirushoerieaetecathanzase cote ae ete Carlowrightia

Aphanosperma sinaloensis (Leonard & Gentry) T. F. Daniel

[Carlowrightia sinaloensis Leonard & Gentry]. Herbaceous pe-

rennial, the herbage and flowers appearing with summer rains and

sometimes with spring rains. Leaves thin, relative large, and fall-

ing with the first dry conditions. Corollas white, quickly falling

with daytime heat. Restricted to ca. 0.5 km of shaded canyon

bottom beneath Coccoloba shrubs. F 85-1194, 85-1316. The near-

est known populations are in Canon las Barajitas and the Sierra

Libre. The unusual clavate or T-shaped capsules set Aphano-

sperma apart from Carlowrightia.

Carlowrightia

1. Leaves lanceolate to ovate.

iebeav estlineary seers estes

C. arizonica

.. C. pectinata

Carlowrightia arizonica A. Gray [C. californica Brandegee; C.

cordifolia A. Gray]. Lemilla. Suffrutescent perennial with drought-

deciduous leaves. Growing and flowering primarily during late

12 Richard S. Felger

spring and the summer rainy season. Corollas white with yellow

and purple on the upper lip. The flowers snap open at about

sunrise, then the corollas fall in the daytime heat, usually by mid-

to late morning. Canyon bottom, slopes, and nearby desert. F 84-

614, 85-556.

Carlowrightia pectinata Brandegee. Herbaceous perennial with

slender stems to ca. 1 m. Leaves thin and quickly drought decidu-

ous. Corollas white with a yellow “eye” and lavender nectar-

guides. Grows and flowers primarily during the summer rainy

season. Canyon bottom and lower north-facing slopes; not com-

mon. F 84-603; Starr 216.

Elytraria imbricata (Vahl) Pers. Cordoncillo. Dwarf perennial

herb; growing and flowering primarily during summer rainy sea-

son. Leaves tardily drought deciduous. Flowers blue. Widespread,

common understory plant; shaded canyon bottom, mostly north-

facing slopes, and in nearby desert habitats. F 84-120, 55-862.

Holographis virgata (Benth. & Hook.) T.F. Daniel subsp. virgata

[Berginia virgata Benth. & Hook. var. virgata]. Scarcely woody

dense mound-shaped shrub often | m. Tardily drought deciduous.

Flowers bright rose-pink; flowering response nonseasonal. Wide-

spread and common, mostly in open, xeric habitats; canyon bot-

tom and slopes and nearby open desert. Heavily browsed by cattle,

deer, and rabbits, as evidenced by observations and scat at the

bases of browsed plants. F 4082, 85-565.

Justicia

1. Herbaceous perennials; corollas lavender; capsules glandular.

ee ies oe areentc cence secesancenceenaoete J. sonorae

1’ Shrubs; corollas red-orange to red; capsules not glandular.

2. Twigs pale, densely covered with microscopic hairs (0.05—

0.10 mm); corollas uniformly red-orange ........ J. californica

2' Twigs not noticeably pale, the hairs not especially minute

(0.2-1.0 mm); corollas red with white markings .................

J. candicans

Justicia californica (Benth.) D. N. Gibson [Beloperone californica

Benth.]. Chuparosa; desert hammingbird-bush; sewalulukut “hum-

mingbird flower” (Yaqui). Sprawling shrub to 2+ m, nearly leafless

during drier times of the year; leaf blades often thickish. Flowering

response nonseasonal but often flowers massively in March. Dry

watercourses, especially in the lower canyon and nearby desert. F

85-580; Starr 204.

Justicia candicans (Nees) L.D. Benson [Jacobinia ovata A. Gray;

J. ovata var. subglabrata S. Watson]. Understory shrub 1—1.5 m

with slender stems. Leaves drought deciduous, the leaf blades

thin. Flowering various seasons, especially late fall and early

winter. Most common in the canyon bottom and on north-facing

slopes; absent from the surrounding desert. F 84-92; Starr 205.

Variety subglabrata, described from “near Guaymas,” is of

doubtful significance (Tom Daniel, personal communication, 1985).

Justicia sonorae Wassh. Herbaceous perennial 0.5—1.2 m with

wiry stems. Flowers showy, the corollas lavender with white

nectar-guide streaks on the lip; mass flowering in March. One

small colony in the canyon bottom. F 85-366, 85-1301.

Occurs also on Cerro Tetas de Cabra at nearby Bahia San Carlos.

Previously known only from southern Arizona and northernmost

Sonora in riparian oak woodland and the upper margins of the desert

(Daniel 1984). It thrives under cultivation in southern Arizona, and

although attractive it tends to become weedy. In cultivation it flowers

profusely in spring and mid-fall, sometimes through the winter in

warm, protected habitats. The winter—fall flowers are often cleisto-

gamous.

Ruellia californica (Rose) I. M. Johnst. Rama parda; hupa chumi

“skunk ass” (Yaqui). Scarcely woody shrub 1—-1.5 m. Leaves

strong-smelling, noticeably glandular-sticky, tardily drought de-

ciduous. Corollas lavender, rarely white; various seasons. Mostly

in open, exposed habitats and dryer areas on canyon slopes and

near the canyon bottom; locally abundant. F 1/954; Gallagher

273 (ASU); Starr 713.

Tetramerium nervosum Nees [T. hispidum Nees]. Herbaceous

perennial. Corollas cream and lavender, falling with mid-morning

heat; generally flowers during hot weather, especially after rains.

Often beneath shrubs; canyon bottom and north-facing slopes.

F 84-90, 85-1222.

AMARANTHACEAE—Amaranth Family

1. Annuals.

2. Leaves alternate, green or red-green, glabrous or with short

simple hairs, the surfaces clearly visible; flowers unisexual.

PE Sae Tee CSE CTT TE eS NE ea a SU Se TE en Amaranthus

2' Leaves mostly opposite, densely white-woolly with

branched hairs usually obscuring the surfaces; flowers

bisexual ei rrre. conten csscescote casas tests sastoawet civics sere staetees Tidestromia

1’ Perennials.

3. Herbaceous; perianth firm and tubular. .. Froelichia

3' Shrubs; perianth soft, not tubular, the segments separate.

Bape OHO CoREE Gono o nO IOS aC EERO EE ECL Saa SERA OREO RSSLNSSDEDUONHOSEOSTIONNO Tresine

Amaranthus

1. Monoecious; herbage glabrous; inflorescences “soft,” the

bracts not prickly; pistillate sepals fringed; stamens 3 ..............

ae A. fimbriatus

1' Dioecious; herbage glandular pubescent; inflorescence bracts

rigid, often sharp and prickly; pistillate sepals not fringed;

stamens 5 ....... A. watsonti

Amaranthus fimbriatus (Torr.) Benth. Bledo, quelitillo, fringed

amaranth; wee’e (Yaqui). Hot-weather ephemeral, sometimes per-

sisting until December or even spring. Flowers green and white.

Canyon bottom, mostly in open habitats, sometimes on slopes and

open nearby desert. F 95-60.

Amaranthus watsonii Standl. Bledo, quelite; careless weed, pig-

weed; wee’e (Yaqui). Nonseasonal ephemeral. Flowers green.

Canyon bottom and lower slopes, mostly in areas grazed by cattle,

and often abundant in the nearby open desert. Honeybees collect

the pollen. F 84-146, 94-861.

Froelichia interrupta (L.) Mog. [F- gracilis (Hook.) Mogq.]. Her-

baceous perennial, probably short-lived, mostly growing and flow-

ering with summer rains. Flowers inconspicuous, nearly hidden in

woolly bracts. Not common; rock crevices and ledges on north-

facing slopes and rarely along the canyon bottom. Bertelsen 92-

155; F 85-1320.

Froelichia gracilis is distinguished only by its annual habit. Dis-

tinctions of the related taxa are based on minor and apparently unre-

liable characters (James Henrickson, personal communication,

1994).

Iresine

1. Leaves mostly alternate; sepals glabrous or sparsely

JOWLO XSAN Soscesscaoccoscacsuesaaseotuoococoococadensseoscaocdosdandoc9a I. alternifolia

1' Leaves opposite; sepals usually woolly ...........:0 ee I. calea

Iresine alternifolia S. Watson [Dicraurus alternifolius (S.

Watson) Uline & A. Gray]. Shrub 1.5—2 m with slender stems.

Leaves tardily drought deciduous, turning orange before falling.

The Flora of Canon de Nacapule: A Desert-Bounded Tropical Canyon near Guaymas, Sonora, Mexico 13

Figure 5.

Inflorescences and flowers white. Canyon bottom and north-fac-

ing slopes. F 84-94; Starr 28.

Alternate leaves usually distinguish this species from /. calea;

however, I. alternifolia may have opposite as well as alternate leaves,

even on the upper branches. The leaves of /. alternifolia are usually

smaller and with rounded tips, while those of /. calea are larger and

pointed. /. alternifolia in the Guaymas region tends to have more

elongated and more slender inflorescences and larger leaves than in

Baja California Sur.

Tresine calea (Ibanez) Standl. Shrub 1.5—2 m. Inflorescence and

Vallesia laciniata. Cultivated in Tucson, grown from seed from Canon de Nacapule. Drawing by Kristen Jakobs.

flowers white. Canyon bottom and north-facing slopes; not rare but

not as common as /. alternifolia. F 84-172; Steinmann 13 Mar 1992.

Tresine calea cannot always be readily separated from /. hart-

manii Uline of northwestern Mexico, and they might not be worthy

of differentiation at the species level.

Tidestromia lanuginosa (Nutt.) Standl. Hierba ceniza; honey-

sweet. Hot-weather ephemeral. Flowers minute, yellow. Season-

ally abundant in open, xeric habitats such as the arroyo bed near

the canyon entrance, south-facing slopes, and nearby open desert.

F 85-1123.

14 Richard S. Felger

APOCYNACEAE—Dogbane Family

1. Shrubs usually >1 m; fruits fleshy, indehiscent .... Vallesia

1’ Suffrutescent perennials or shrubs generally <1 m; fruits dry,

dehiscent.

2. Suffrutescent perennials; leaves often alternate, the blades

thin; flowers bright yellow, the floral tube ca. 1 cm;

capsules 2.0-2.5 mm in width; seeds with a tuft of hair at

LOXOLIIOL GITG IS <ccecacasnéaoccnaesoaosasnccenssoscs6cos6oqqdee0906500000000 Haplophyton

2' Small woody shrubs; leaves opposite, the blades rather

thick; flowers white, the floral tube 6.5—12 cm; capsules >5

mm in width; seeds with a tuft of hair at one end only..........

Telosiphonia

Haplophyton cimicidum A. DC. var. cimicidum. Hierba de la

cucaracha; cockroach plant. Herbaceous perennial. Leaves

drought deciduous. Flowering mostly during warmer months.

Canyon bottom, slopes, and floodplain and hills near the canyon

entrance. F 84-122; Starr 25.

Telosiphonia nacapulensis Felger & Henrickson, Aliso 14:194,

1996. Shrub to 1 m, the branches divaricate, rigid, and woody.

Leaves tardily drought deciduous. Flowers white and showy, often

3-5 cm wide, fragrant, mostly opening in the late afternoon and

fading the following morning; flowering more or less throughout

the summer rainy season. Fairly common on open rocky slopes,

ledges, and cliffs at various exposures. F 85-830 (holotype, ARIZ;

isotypes, GH, MEXU, NY, TEX), F 85-869, 92-1034.

Occurs in the Sierra El Aguaje, from the vicinity of Bahia San

Carlos and Nacapule northward to Bahia San Pedro, and in the Sierra

Libre. Its closest relative seems to be T. brachysiphon (Torr.)

Henrickson [Macrosiphonia brachysiphon (Torr.) A. Gray], a herba-

ceous perennial of northern Sonora, Chihuahua, Arizona, and New

Mexico (Henrickson 1996).

Vallesia

1. Leaves 3.3—8 cm; stipules 1.3—1.5 mm, the margins nearly

entire; corolla tube 3.6—4.3 mm V. glabra

1’ Leaves 5-12 cm; stipules 1.5—3.0 mm, the margins laciniate;

Corollaitube!9!S=NOSMI.ce.cescsscescosceseceressececescessss V. laciniata

Vallesia glabra Cay. Citabaro, huevito; sita’avao (Yaqui). Shrub

to 2.5 m, essentially evergreen. Flowers white; various seasons.

Rare, with several widely scattered young plants in areas of cattle

grazing in the arroyo below the canyon entrance and at the spring.

It has spread into the canyon area within about the last decade,

apparently as a result of cattle grazing. Common in nearby areas of

San Carlos and Guaymas. F 95-43, 95-60.

Vallesia glabra can be distinguished from V. laciniata by its

smaller and shinier leaves and smaller flowers. The two species do

not grow intermixed.

Vallesia laciniata Brandegee [V. baileyana Woodson, Ann. Mo.

Bot. Gard. 24: 14, 1937]. Fig. 5. Nacapule jasmine. Shrub to 3-4

m, with multiple stems, the branches flexible, with age becoming

woody especially near the base. Leaves essentially evergreen,

alternate, the blades 4.4-11.3 x 1.3—2.7 cm, lanceolate, the upper

surfaces glabrous or minutely puberulent, especially along the

midrib, the lower surfaces short-pubescent, the petioles 5-10 mm,

relatively thick; stipules triangular, laciniate, yellowish, soon be-

coming brown.

Inflorescences subumbellate, often of two short dichotomous

branches, the clusters often 4-6 cm across, each with 10-25 flowers.

Peduncles 12.5—23.5 mm, erect, firm, with minute scales. Flowers

with strong gardenia-like fragrance day and night, the nectar sweet-

tasting. Each flower subtended by scales resembling the stipules.

Calyx green, the tube swollen, 0.8—1.0 mm, the lobes triangular-

acute, 0.8—1.2 mm. Corolla tube at first green, becoming white dur-

ing or just after anthesis, 10.0-10.5 mm, narrowed to 0.8—1.5 mm

wide below, conspicuously swollen above to 2.5—2.7 mm wide, the

tube wall thickened here to 0.3 mm thick, the tube constricted to 2.0

mm in width at apex of throat. Corollas otherwise pure white, fading

yellowish when dried, with a star-shaped slightly thickened callus of

white glistening and erect hairs surrounding the throat orifice, the

lobes spreading, each 7—7.5 mm, the margins inrolled above. Anthers

yellow, 1.4-1.6 mm, tapered above, the filaments shorter than an-

thers, the stamens inserted on throat of corolla tube. Style 6 mm,

whitish below, the stigma green, |.3—1.4 mm, cylindrical and thick,

enveloped in a clear jellylike substance, notched above. Flowering

any time of year, often profusely March—April. Fruits paired or one

fails to develop, one-seeded drupes 10-13 mm, the pericarp fleshy,

translucent whitish to whitish pink. Seeds (9) 10-12 mm, oblan-

ceolate, white, and bony, the surfaces with a raised dendritic—reticu-

late pattern.

Locally dense along the canyon bottom and in pockets of dense

brushy vegetation on the lower north-facing slopes; essentially re-

stricted to the winter-shaded portion of the canyon. Bailey s.n., 30

Mar 1934 (type of V. baileyana, MO, not seen); F 84-110; Gentry

19880; Van Devender 84-255.

The fruits are eaten by coyotes and other animals, and the seeds

seen in their scat along the canyon-bottom trail and trails leading out

of the canyon. Seed-grown plants are cultivated to a limited extent in

Tucson gardens but are sensitive to freezing temperatures. Vallesia

laciniata can also be propagated by cuttings in a greenhouse mist-

bench with bottom heat. The luxuriant foliage and spectacularly

sweet-scented flowers make it worthy of extensive cultivation in

Sonora and other arid and semi-arid tropical regions.

Vallesia laciniata was previously known only from Canon de

Nacapule, but recently I found scattered plants in Canon las Barajitas

and at Los Anegados on the seaward side of the Sierra El Aguaje.

Apparently it also occurs in the Sierra Libre (Alberto Burquez, per-

sonal communication, 1996). Williams (1996) suggested that V.

baileyana may be a synonym of V. laciniata, described from Baja

California Sur. Lagree, although V. laciniata tends to have more con-

spicuously pubescent, herbage. Williams also suggested that V.

conzattii Standl. might be another synonym of V. laciniata, thus giv-

ing ita rather wide distribution in mainland Mexico. Woodson (1937)

mentioned affinities with V. flexwosa Woodson of Costa Rica and V.

montana Urban of Hispaniola.

ARISTOLOCHIACEAE—Birthwort Family

Aristolochia watsonii Woot. & Standl. [A. brevipes Benth. var.

acuminata 8. Watson; A. porphyrophylla Pfeifer]. Hierba del indio;

Indian root; bwasubwila (Yaqui). Drought-deciduous herbaceous

perennial from a thickened tuberous root. Stems sprawling or short-

vining. Flowering with warm weather. Canyon bottom and slopes

and rock crevices on north-facing canyon wall. F 85-239; Starr 213.

ASCLEPIADACEAE—Milkweed Family

Ibe ISISTNS THO LE WALTON: cccoccacoascoceonsoccoadeadeoneoobodoescacsnedoosnondon00 Asclepias

1' Vines with the stems twining, at least at the tips.

2. Leaves linear to lanceolate, more than twice as long as

wide, the margins often revolute.

3. Stems with a longitudinal line of usually curved hairs;

flowers 4 mm, the inner petal surfaces obscured by hairs.

oo Hey ave cues Seegav fa sete steed eclewesSiaetvseestasses eottestsecre oozes Metastelma

3’ Stems essentially glabrous or sparsely pubescent with

scattered straight hairs; flowers >5 mm, the petal surfaces

Readily WASIblemewenceecercestescestce teeeee eens Sarcostemma

2' Leaf blades broadly ovate to cordate, less than twice as long

as wide, the margins not revolute.

4. Herbage essentially glabrous; leaves cordate at base;

The Flora of Canon de Nacapule: A Desert-Bounded Tropical Canyon near Guaymas, Sonora, Mexico 15

fruits at least 2. cm in diameter, tough and leathery to

PETTERS 1X2) 1A on.s3coosoeoo0ecanboconoecsacacconsEsHeRCSTHecOoSOCCOO Marsdenia

4' Herbage conspicuously pubescent; leaves rounded to

obtuse at base; fruits to 1.5 cm in diameter, soft-walled.

Recon oSoCae oo La oca a OEE co OECOO ROCCO SUE CECE eeeoCereEr ea Matelea

Asclepias—Milkweed

IN JONAS {35 1(0) Toa TT scoscasccoaoconcanacsonp0cxDcaseGaNbcHNedoooRKeCK A. leptopus

WVBR EIRS S511) TWAT oaccoosocdencbaoccsdosDecoosoacaeocadnDbb30E0d000¢00 A. subulata

Asclepias leptopus |. M. Johnst. Cliff milkweed. Suffrutescent

perennial, much smaller than A. subulata. Stems very slender,

ascending to upright and drooping during drought. Leaves few,

filiform, and quickly deciduous. Flowers white and green; various

seasons. Rock crevices, mostly on north-facing canyon walls but

also on arid, exposed rock faces. Larvae of Danaus gillipus

strigosus feed on the herbage, and the butterflies visit the flowers. F

84-147; 12 Oct 1897, Palmer 256 [ARIZ, DS, UC, US; the labels

on the DS and UC specimens read “Guaymas,” while the ARIZ and

US specimens are labeled “near Nacapuly, 15 miles west of

Guaymas.” Also see Johnston (1924:1127) and Mc Vaugh (1956)].

Asclepias subulata Decne. Mata candelilla, yamate, reed-stem

milkweed. Perennial with many semi-succulent erect stems.

Leaves few, filiform, and quickly deciduous. Flowers cream-

white; various seasons; visited by large orange-winged tarantula-

hawk wasps (Pepsis). Widely scattered on open desert near can-

yon mouth. F 94-858.

Marsdenia edulis S. Watson. Talayote. Large perennial vine, the

base often woody with winged corky bark; leaves tardily drought

deciduous. Flowers white with pale pink; at least following sum-

mer rains. Fruits 8-10 cm, ellipsoid and green. Canyon bottom

and mostly north-facing slopes. F 85-866.

Matelea cordifolia (A. Gray) Woodson. Talayote. Perennial, often

growing through shrubs and trees with drought-deciduous broadly

ovate pale green leaves, foul smelling when bruised or crushed.

Flowers cream color with a green corona. Herbage, flowers, and

fruits produced at various seasons following rainy periods. Mainly

canyon bottom and north-facing slopes; less common on south-

facing slopes. F 84-621; Phillips 75-142.

Metastelma arizonicum A. Gray [Cynanchum arizonicum (A.

Gray) Shinners; Metastelma watsonianum Standl.; M. albiflorum

S. Watson, 1889, not M. albiflorum Griseb., 1861]. Small peren-

nial vine growing in shrubs; leaves tardily drought deciduous,

narrow and dark green with revolute margins. Flowers 3-4 mm,

green except densely white villous on the inner surface of the

corolla lobes. The hairs point downward and toward the center of

the flower. A small insect attracted to the flower is thus directed

toward the center, and the downward-pointing hairs prevent its

access elsewhere. Flowering during warmer months. Scattered on

canyon slopes. F 85-560.

Sarcostemma cynanchoides Decne. subsp. hartwegii (Vail) R. W.

Holm. Guirote; climbing milkweed; maso pipi (Yaqui). Perennial

vine. Flowers maroon-purple and white; any season. Canyon bot-

tom and arroyos in nearby open desert. F 84-/23.

ASTERACEAE (COMPOSITAE)—Composite

or Daisy Family

1. Perennials; stems semi-succulent, the leaves succulent ............

Wedesnane tenets rc tecceduates Mecdee nets sceeaeer, Petes ened a ener eee Hofmeisteria

1’ Annuals or perennials; not succulent.

2. Annuals; sap milky; florets all conspicuous and similar in

shape (inner florets often smaller), ligulate (ligules 5-lobed,

strap-shaped), and bisexual.

3. Achenes (cypselas) beaked, the beak slender like a wire

and about as long as or longer than the achene body..........

SCE Rabo OS HOSE EOD COS CENCE EASaE Conca acndoaOtoacadecac ACh AGroe CRETE Lactuca

3’Achenes not beaked (sometimes narrowed to a neck but

the neck not slender like a wire and much shorter than the

Achene! body aie eas essere eerie cee Sonchus

2’ Annuals or perennials; sap not milky; florets not all ligulate,

the heads with (1) both ray florets (with a strap-shaped, 3-

lobed corolla, and pistillate or sterile) and disk florets (with

a tubular, 5-toothed corolla, and usually bisexual), or (2)

only disk or disklike florets, the corollas showy to reduced

or lacking, or (3) bilabiate (two-lipped) florets only.

4. Leaf bases persistent on stems as short, blunt projec-

tions; heads of bilabiate florets only; achenes expanded

at apex into a disk bearing numerous pappus bristles.

Fecha RRR e once oR Bee rehicacr herent eoccenass snc cea CeoCLE ER a COECE Trixis

4' Leaf bases not persistent as above; heads with ray and

disk florets, or only disk or disklike florets, these not

bilabiate; achenes various.

5. Heads with both ray and disk florets, the rays

usually obvious (taxa with small, inconspicuous, or

early-deciduous rays will key out in either choice; if

in doubt, best to go to 5’).

6. Pappus none.

7. Leaves alternate.

8. Plants annuals or short-lived herbaceous

perennials; leaves dissected; rays white with

dark longitudinal lines ............... Coreocarpus

8’ Plants shrubby or subshrubby; leaves entire;

rays yellow.

9. Herbage not viscid; leaves ovate; rays >10

LITT esas bcBendaaan co SsObR BCAA ooeC Se AaOADERO ISA CGCO Encelia

9' Herbage viscid-sticky; leaves linear; rays

<3) TOTEM. cacecsocnadancaeascceoaeeaecoa3d Gymnosperma

7' Leaves opposite.

10. Rays white, minute, and not persistent.........

tS SD, SS, ESO Rei oceans ede Eclipta

10’ Ray yellow, fading greenish, showy, and

PELSISLEN eee eee eee Heliopsis

6’ Pappus present, at least on disk achenes.

11. Plants glabrous and dotted with prominent oil

glands, pungently aromatic.

12. Leaves deeply divided; rays white ...............

eect Sea eee ea eee eee iets Thymophylla

12’ Leaves entire but some with basal bristles;

all flowers yellow.

13. Annuals; leaves with prominent bristles at

base 25 eee Saree eee Pectis

13’ Perennials; leaves without bristles ...........

... Porophyllum

11’ Plants pubescent or nearly glabrous, not dotted

with oil glands and not pungently aromatic.

14. Plants glabrous except woolly tufts at leaf

bases and axils; pappus of many long soft

Wibiteshains eens seeece eee Senecio lemmonii

14’ Herbage pubescent throughout; pappus of

scales and sometimes also bearing | or 2

awns or bristles.

15. Annual or perennial herbs; leaves

palmately lobed and coarsely toothed:

florets without chaffy bracts .......... Perityle

15’ Perennials, herbaceous or shrubby; leaves

entire to minutely toothed; disk florets

subtended by chaffy bracts, these enclos-

ing the achenes and falling with them........

Unie, MANS rei ea wee: Viguiera

5' Heads of disk florets only, outer florets without an

16 Richard S. Felger

obvious ligule or ray, or if ray florets present then

inconspicuous or reduced, or lacking a well-

developed ligule (if in doubt about presence of rays

then take this choice).

16. Heads unisexual, the pistillate florets in a bur .....

SRS cEROSCEL Ee Acer ce tis MORSE Lboeee OSE ECEOA Ambrosia

16' Heads not unisexual; none of the florets in burs.

17. Annuals; leaves sessile or nearly so, the

margins entire or nearly so; florets minute,

inconspicuous, and dull-colored (rarely reddish

on tips); achenes | mm or less.

18. Majority of bracts of head partially or

completely enclosing a floret; outer several

f florets without pappuS............... cee Filago

18’ Majority of bracts of head not directly

associated with florets; all florets with

pappus.

19. Plants sparsely pubescent, not at all

woolly; leaves with a few shallow teeth.

Be pect honce ca secera aot See ony Ea Conyza

19’ Plants densely white-woolly; leaves

entire A Gnaphalium

17’ Annuals and perennials; leaves sessile or not,

the margins entire or not; florets small or

medium-sized, often colorful, greenish, yellow,

white, or pink; achenes 2 mm or more, or if

smaller then perennials.

20. Annuals or perennials; pappus none.

21. Herbs, mostly annuals, not viscid-sticky;

leaves opposite; outer florets white, the

CentralfonesivellOwaeeeersscsees ees Eclipta

21’ Perennials, shrubs or subshrubs with

viscid-sticky herbage; leaves alternate; all

florets yellOW ........-eeeeeeeeeee Gymnosperma

20' Perennials, pappus present.

22. Stems conspicuously winged.

23. Leaves alternate, soft-pubescent and

glandular, the margins finely toothed;

ION ETES) JONIIT < oeacconceesacscadsoanqdncocndas Pluchea

23' Leaves opposite, densely scabrous-

hispid, the margins coarsely lobed and

toothed; flowers yellow .......... Verbesina

22’ Stems not winged.

24. Heads unisexual; vegetative parts

(herbage and phyllaries) resinous-

glutinous and aromatic; flowers dull

Witte ee eR roe ecsevciesomes Baccharis

24' Heads bisexual; herbage and phyllaries

not resinous-glutinous.

25. Many-stemmed perennial bushes;

pappus of plumose bristles ..... Bebbia

25' Annuals or perennials; pappus not

plumose.

26. Pappus of uniform, slender,

capillary bristles.

27. Heads clearly multiple-

flowered and on separate

peduncles; dull flowers yellow-

PARES cooncaosapcadedsads2d000008 Brickellia

27' “Heads” actually a globose

collection of small single-

flowered heads; flowers bright

WEIUIOKY casccccendacensoGo00050005 Lagascea

26' Pappus with scales or broad

bristles in addition to slender

bristles.

28. Leaves entire or nearly so, the

petioles shorter than the leaf

blades; heads 4 mm. Eupatorium

28' Leaf margins crenate to

toothed, the petioles mostly

longer than the leaf blades; heads

8-10 mm............... Pleurocoronis

Ambrosia

1. Herbaceous perennials, the stems dying back to the ground

after fruiting; leaves 1- to 3-times pinnately divided.................

SA et crane eR eae BAT tate RCSL Bec ACO aSEERCOOS A. confertiflora

1’ Bushy or shrubby, the stems more or less perennial; leaves

crenate to shallowly lobed.

2. Leaf blades elongate-triangular, longer than wide................-

a: A. ambrosioides

2' Leaf blades ovate-cordate, about as wide or wider than long.

Eee rae does eae ea eee Sea Tanz te dan Tee ERE A. cordifolia

Ambrosia ambrosioides (Cav.) W. W. Payne [Franseria ambro-

sioides Cav.]. Chicura; canyon ragweed; hiowe (Yaqui). Shrub

1.5—2 m with many slender stems. Leaves partially evergreen but

reduced in size and number during drought, the blades usually

with insect damage and studded with insect galls. Flowers in

spring. Infrequent along the canyon floor and the open desert;

more numerous in nearby arroyos. F 94-861; Gentry 19879.

Ambrosia confertiflora DC. Estafiate; slim-leaf ragweed; chi-

chivo (Yaqui). One colony ca. 1 m across, adjacent to Coccoloba

goldmanii and Vallesia laciniata in disturbed areas at edge of

road; not seen elsewhere in the canyon. This weedy plant was first

found in the canyon in 1992. F 92-1021.

Ambrosia cordifolia (A. Gray) W. W. Payne [Franseria cordifolia

A. Gray]. Bushy perennial ca. | m. Growing and flowering with

cool-season rains, and essentially leafless during the summer. Can-

yon floor and north-facing slopes; not common. F 11990, 95-7.

Baccharis sarothroides A. Gray. Romerillo; desert broom; heeko,

heko (Yaqui). Broomlike shrub, several plants to 2 m, mostly

much smaller; flowers cream-white. Scattered along the canyon

bottom in open, grazed, and disturbed areas. First seen in the

canyon in 1985. F 92-1038, 94-873.

Bebbia juncea (Benth.) Greene var. aspera Greene. Hierba

ceniza; sweetbush; maso kuta (Yaqui). Suffrutescent bushy peren-

nial, often 1-1.5 m. Leaves usually sparse and quickly drought

deciduous. Flowers yellow, fragrant; almost any time of the year.

South-facing slopes and the nearby open desert. F 85-569.

Brickellia

1. Leaf margins coarsely toothed; outer phyllaries ca. 1.0 mm

wide; achenes (3.0) 3.5-4.0 MM... cess B. coulteri

1’ Leaf margins blunt-toothed to scalloped; outer phyllaries 1.2—

1.4 mm wide; achenes 2.2—2.9 mm ..............00: B. rhomboidea

Brickellia coulteri A. Gray var. coulteri. Shrub 1—2 m with slen-

der brittle stems. Leaves gradually drought deciduous. Flowers

rather inconspicuous, yellow-green and purple; nonseasonal. Can-

yon bottom and slopes and nearby open desert. F 84-157; Van

Devender 28 Dec 1982.

Brickellia rhomboidea Greene, 1890 [B. floribunda A. Gray].

Sprawling shrub 1.5-2+ m across, scarcely woody at the base and

with whitish stems. Leaves nearly evergreen or perhaps deciduous

in extreme drought, highly variable in size and shape. Phyllaries

green, the flowers yellow-green; flowering at various seasons.

Distinguished from B. coulteri by its thicker stems and larger,

broader, thicker, generally more obtuse leaves with smaller, shal-

lower, and blunter marginal teeth, less glandular, broader (espe-

The Flora of Canon de Nacapule; A Desert-Bounded Tropical Canyon near Guaymas, Sonora, Mexico 17

cially the outer) phyllaries, and smaller achenes with denser and

longer hairs.

Several colonies along the canyon bottom and at a shaded seep

on a north-facing rock face near the upper end of the canyon. Known

from the Guaymas region. F 84-/57, 84-582, 85-1307.

Brickellia macromera B. L. Rob., 1917, of the eastern side of

Baja California Sur is perhaps not distinct from B. rhomboidea. The

differences in leaf character given by Wiggins (1964) do not hold up.

However, there are differences in achene size: B. macromera achenes

are ca. 3.6 mm, while those of B. rhomboidea are ca. 3.0 mm. B.

rhomboidea also seems very closely related to and perhaps conspe-

cific with B. brandegei B. L. Rob., 1917, from Baja California Sur,

southwestern Sonora, and northwestern Sinaloa. B. rhomboidea is

distinguished from B. brandegei by its smaller heads and achenes.

*Conyza canadensis (L.) Cronquist var. glabrata (A. Gray)

Cronquist. Cola de caballo; horseweed. Warm-weather annual.

Flowers white, inconspicuous; fall. First found in the canyon in

1985 as one colony in wet soil in the bottom of the upper part of

the canyon in an area heavily grazed by cattle. F 85-/300.

Coreocarpus sonoranus Sherff. Ephemeral to short-lived peren-

nial. Leaves drought deciduous, thin to sometimes semi-succu-

lent. Rays white with dark purple lines, the disk yellow; appar-

ently nonseasonal depending on soil moisture. Canyon bottom,

often in shade. F 84-604, 92-1037.

*Eclipta prostrata (L.) L. [E. alba (L.) Hassk.]. Chile de agua;

false daisy. Nonseasonal ephemeral. Flowers white; more or less

continuously during warm weather. Wet soil in the canyon floor in

the vicinity of Ficus insipida and Washingtonia. F 84-153; Phillips

75-172.

Encelia farinosa A. Gray var. farinosa. Incienso, rama blanca;

brittlebush; toroko huya, kopal ouwo (Yaqui). Small shrub; rays

and disk yellow; spring and with summer or fall rains. Abundant in

the open desert and on drier exposed slopes. F 95-106.

Eupatorium solidaginifolium A. Gray. Suftrutescent perennial.

Leaves nearly evergreen. Flowers whitish, inconspicuous. Shaded

north-facing slopes near the canyon floor and occasionally among

dense vegetation in shaded areas of the canyon floor. Widespread

in western Mexico and southwestern United States. In the San

Carlos—Guaymas region I have found it only at Nacapule and on

Cerro Tetas de Cabra. F 11996, 85-863.

Filago californica Nutt. California fluffweed. Small slender

white-woolly winter-spring ephemeral. Open desert habitats near

the canyon mouth and open areas along the canyon bottom. F 85-

244A.

Gnaphalium sphacilatum Kunth [G.. pedunculosum 1. M.

Johnst.]. Small densely white-woolly winter—spring annual. Can-

yon bottom, especially near the entrance; apparently uncommon.

F §5-244B.

Gymnosperma glutinosum (Spreng.) Less. [Selloa glutinosa

Spreng.]. Annual or suffrutescent perennial; herbage sticky-gluti-

nous, the flowers yellow. Locally rare; canyon bottom near

Washingtonia and Ficus insipida trees in areas heavily grazed by

cattle. First seen in the canyon in 1992. F 92-/029.

Heliopsis anomala (M. E. Jones) B. L. Turner [H. rubra T. R.

Fisher; H. parvifolia A. Gray var. rubra (T. R. Fisher) B. L.

Turner]. Winter—spring annual to short-lived perennial. Flower

heads solitary on long peduncles, the flowers bright yellow; No-

vember—April. Scattered along the canyon floodplain; seldom

common. F 95-5.

Hofmeisteria crassifolia S. Watson. Small globose perennial with

succulent leaves and stems. Nearly evergreen but leaves reduced

in size and number during drought. Flower heads solitary on long

stalks, the rays lavender-pink, the disks white; at least February—

April and October. Rock crevices, mostly on north-facing cliffs.

Burgess 6379; Van Devender 84-254.

*Lactuca serriola L. Prickly lettuce, compass plant. Annual, ger-

minating in late winter or spring, flowering in late spring. Flowers

pale yellow. Rare; first found in 1995, along the road in the canyon

bottom. F 95-/19.

Lagascea decipiens Hemsl. var. glandulosa (Fern.) Stuessy. Shrub

1.5-2.5 m. Leaves tardily drought deciduous. Flowers bright yel-

low; nonseasonal except in extreme drought. Mostly along the

canyon bottom and north-facing slopes. F 84-167, Phillips 75-

167.

Pectis rusbyi A. Gray [P. palmeri S. Watson]. Manzanilla del

campo; wo’i si’iya (Yaqui). Summer—fall ephemeral with pun-

gently aromatic herbage. Flowers bright yellow. Canyon floor

near the entrance and the open desert. One of the most abundant

summer wildflowers in the region. Burgess 6530.

Perityle

1. Rays white, the disk flowers yellow ...........:.c:eeeeeeeees P. emoryi

1’ Ray and disk flowers bright yellow.

Pes J NONE NSS TANTS: <S) THIS coccoccseccocococeesaccaccassooceccec1 P. californica

2' Perennials from a woody base and also flowering in first

SEASONS TENTS LE ERASE 7/ TIEN, coceoocoeesccccoxcaococanocodes P. leptoglossa

Perityle californica Benth. Mansaniata saila (Yaqui). Cool-

weather ephemeral. Canyon bottom, slopes, and open desert; often

seasonally abundant. F 84-///, 85-555.

Perityle emoryi Torr. Desert rock daisy. Spring ephemeral. Can-

yon bottom near entrance. F 85-584B.

Perityle leptoglossa Harv. & A. Gray subsp. palmeri (S. Watson)

Felger & Lowe [P. palmeri S. Watson]. Herbaceous perennial, also

flowering in the first season. Flowering response apparently non-

seasonal, at least during the cooler months, late spring, and fall.

Steep rocky slopes, crevices on north- and east-facing cliffs, and

on large rocks in the canyon bottom. F 85-262.

Pleurocoronis laphamioides (Rose) R. M. King & H. Rob. [Hof-

meisteria laphamioides Rose]. Perennial subshrub, subglobose, ca.

80 cm across, the leaves semi-succulent, ultimately drought decidu-

ous. Flowers white to pale yellow with purple stigmas; various

seasons. North-facing rock walls of canyon. F 92-1053, 94-856.

Pluchea salicifolia (Mill.) S. F. Blake [P adnata Willd.; P.

parvifolia (A. Gray) Godfrey; P. adnata var. parvifolia (A. Gray) S.

F. Blake; P. salicifolia var. parvifolia (A. Gray) S. F. Blake; P.

subdecurrens Cass. var. parvifolia A. Gray; P. subdecurrens var.

canescens A. Gray]. Sprawling shrub to 2 x 3 m. Stems brittle and

winged from decurrent, sessile leaves, the leaves evergreen or nearly

so and pungently aromatic. Flowers pink, the florets ca. 200+ per

head; flowering in warmer months. A vigorous but highly localized

population of several dozen shrubs in the upper reaches of the

canyon at seeps and along the streambed beneath Washingtonia

palms. F 54-/44, 84-583. Not known elsewhere within the Sonoran

Desert in Sonora. It occurs in subtropical regions of Baja California

Sur and from southern Sonora to Guatemala.

Pluchea adnata var. parvifolia was previously considered en-

demic to Baja California Sur. Godfrey (1952) treated P. parvifolia as

a species distinct from P. salicifolia. | cannot distinguish Nacapule

specimens from those of Baja California Sur and believe them to be

Figure 6. Verbesina felgeri. Drawing from holotype by Linda Vorobick (from Turner 1985).

The Flora of Canon de Nacapule: A Desert-Bounded Tropical Canyon near Guaymas, Sonora, Mexico 19

conspecific with P. salicifolia. Reported differences, including size

of the heads, did not hold up when I examined a suite of specimens

larger than was available to Godfrey.

Porophyllum pausodynum B. L. Rob. & Greenm. [P. brachypodum

B. L. Rob.]. Maso kuta (Yaqui). Short-lived perennial often ca. | m,

with the pungent aroma characteristic of the genus. Leaves tardily

drought deciduous. Flowers yellow; apparently nonseasonal. Rock

crevices, often on north-facing slopes. F 84-/08, 85-563.

Senecio lemmonii A. Gray. Lemmon groundsel. Winter—spring

ephemeral. Leaves thin. Flowers bright yellow. Rare, in the can-

yon bottom mostly in shade. F 84-579, 85-263.

*Sonchus oleraceus L. Chinita; common sow-thistle; korai

(Yaqui). Winter—spring ephemeral. Flowers pale yellow. Scattered

along the canyon bottom. A common weed in the region. F 85-

253, Van Devender 84-242.

Thymophylla concinna (A. Gray) Strother [Dyssodia concinna

(A. Gray) B. L. Rob.]. Manzanilla del coyote; wo’i si’iya (Yaqui).

Winter—spring ephemeral dotted with small oil glands and pun-

gently aromatic. Rays white, the disk yellow. Mostly on sandy or

gravelly soils; canyon entrance, nearby south-facing slopes, and

the open desert.

Trixis californica Kellogg var. californica. Scarcely woody bushy

perennial. Flowers yellow; nonseasonal but especially in spring.

Common and widespread, mostly on slopes and in the surrounding

desert. F 85-571, 85-859.

Verbesina felgeri B. L. Turner, Phytologia 57:127, 1985. Fig. 6.

Suffrutescent to shrubby perennial, probably short-lived, to ca. 1 m;

eventually drought deciduous or dying back to near ground level in

extreme drought. Flowers bright yellow; apparently at various sea-

sons depending on soil moisture. Known only from Canon de

Nacapule and a second population recently discovered in Canon los

Anegados near Aguaje de Robinson in the middle of the Sierra El

Aguaje (Alberto Burquez, personal communication, 1997).

In 1984 I found less than one half dozen plants in the shade be-

neath dense canyon-bottom vegetation adjacent to the north-facing

wall in the lower part of the canyon. Subsequently, during a wetter

year, approximately 65 plants were located in the same area. Several

plants were grown from cuttings from the type collection, and these

propagated in cultivation from cuttings and seed. The plants have

been distributed to botanic gardens and plant nurseries in southern

Arizona and Sonora. According to Turner (1985), V. felgeri “has no

strikingly close relatives” and is in the section Pterophyton, which is

centered mostly in Jalisco and surrounding areas. F 84-97 (TEX,

holotype; isotypes: ARIZ, MEXU, RSA), 85-1125, 85-1327.

Viguiera dentata (Cav.) Spreng. var. dentata. Straggly annual to

short-lived herbaceous perennial; tardily drought deciduous.

Flowers yellow. Locally rare in the canyon bottom in shade be-

neath trees and shrubs. F 84-/01, 85-1224.

I have not seen V. dentata elsewhere in the Guaymas region. It

usually occurs as a robust many-flowered perennial outside the

desert, as in tropical deciduous forest in southeastern Sonora and oak

woodland in Sonora and Arizona.

BORAGINACEAE—Borage Family

1. Woody shrubs or small trees .......0...ccceeceeeeeeeseeeeeeeees Cordia

1. Herbaceous annuals or perennials.

2. Fruits broadest below middle; calyx tightly enclosing the

nutlets, the calyx lobes obviously longer than the mature

nutlets; nutlets muricate and glabrous ................. Cryptantha

2' Fruits broadest at about middle; calyx not tightly enclosing

the nutlets, the calyx lobes obviously shorter than the

mature nutlets; nutlets pubescent .............0.+ Heliotropium

Cordia

1. Leaves mostly <3 cm, rough-pubescent, the margins toothed.

BOLE RECCEEEOOC CAPER ELSE CEE CEC RECEECE ROL PCCERCCE CCCP SHEE C. parvifolia

|’ Leaves mostly >6 cm, glabrous or nearly so except petioles,

themmarsinstentitests.s sneer eee ee eee eee C. sonorae

Cordia parvifolia A. DC. Vara prieta; littleleaf cordia; wotovo

(Yaqui). Shrub often 1.5—2+ m with hardwood stems and dark

bark; drought deciduous. Flowers white, showy, opening an hour

or so after dawn and falling with mid-day or afternoon heat; mass

flowering following rains at almost any time of year except mid-

winter. Canyon entrance and nearby open desert. F 85-837.

Cordia sonorae Rose. Palo de asta; pomahe (Yaqui). Large shrub

to small tree 3-6 m; tardily drought deciduous. Flowers white;

March-April. The fruits, not described previously, are one-seeded

nutlets (the pericarp very thin, quickly drying), ripening in early

summer, 6.0—7.0 x 3.9-4.2 mm, broadly ellipsoid, mottled tan and

brown or red-brown, essentially smooth to faintly ribbed, mi-

nutely papillate, the dried style base forming an oblique, persistent

knob at the fruit apex; fruit tightly held in the persistent calyx and

corolla to form a parachutelike dissemination unit. Lower north-

facing slopes. Burgess 6378; Van Devender 84-249.

Cryptantha

1. Nutlets heteromorphic, the odd nutlet largest ....C. angustifolia

1’ Nutlets homomorphic, the nutlets all similar ............... C. grayi

Cryptantha angustifolia (Torr.) Greene. Narrowleaf cryptantha,

desert cryptantha. Winter—spring ephemeral. Inflorescence

branches coiled, the flowers white; nutlets 4. Canyon bottom near

entrance and nearby open desert. F 85-237B.

Cryptantha grayi (Vasey & Rose) J. F. Macbr. var. cryptochaeta

(J. F. Macbr.) I. M. Johnst. Winter—spring ephemeral, generally

smaller and more delicate than C. angustifolia. Inflorescence

branches moderately coiled, the flowers minute, white; nutlets 4.

Canyon bottom near entrance and nearby open desert. F 85-237A.

Heliotropium procumbens Miller. Annual or perhaps short-lived

perennial. Flowers white. Canyon bottom. Locally rare; small

first-season plants fruiting in October (elsewhere perennial but

often flowering in the first season). F 84-162.

BRASSICACEAE (CRUCIFERAE)—Mustard Family

1. Herbage with dendritic (branched) hairs; fruits 3.5—12 mm .....

Medea gaeslesuve ued coahies Sugutbamedite dese base aites pasties codevasnodea sues tes Descurainia

1' Herbage glabrous or with simple hairs; fruits at least 20 mm.

2. Petals white to lavender, at least 6 mm, conspicuously lobed.

PD eR co eee a chee reer cee eee ee: Dryopetalum

2' Petals yellow, 3-4 mm, not lobed...................26- Sisymbrium

Descurainia pinnata (Walter) Britton. Tansy mustard; aasam,

huya aasam (Yaqui). Winter-spring ephemerals. Flowers minute,

pale yellow. Mostly along canyon bottom in open areas and nearby

open desert. F 85-249.

Dryopetalum runcinatum A. Gray var. laxiflorum Rollins. Winter—

spring ephemeral, sometimes germinating in mid-October. Herbage

glabrous or essentially so when shaded and well watered, generally

hirsute with simple white hairs in harsher conditions. Flowers attrac-

tive, white or suffused with pink-purple; December—March. Canyon

bottom and north-facing slopes. F 85-242; Reina 95-155; Starr 207.

Plants in the Guaymas region have been referred to D. palmeri

(S. Watson) O. E. Schulz (Rollins 1941). Iam unable to disinguish

these specimens from D. runcinatum var. laxiflorum.

*Sisymbrium irio L. Pamita; London rocket; wikit woki (Yaqui).

Winter-spring ephemeral. Common along the canyon bottom,

especially in areas of cattle grazing. F 85-265.

20 Richard S. Felger

BURSERACEAE—Torchwood Family

1. Bark not exfoliating or peeling; fruits bivalvate with a thin

fleshy orange aril covering one-half to two-thirds of the

blackish seed; leaves usually bipinnate (occasionally pinnate

OP {lit OSOTTFENK)) scccesecoccasscecsooso0box5 nocococoa7eo.pqdS9adaduGees03aN B. laxiflora

1' Bark exfoliating in papery flakes or sheets especially during

dry seasons; fruits trivalvate with a thin papery aril covering

the light-colored seed; leaves once pinnate.

2. Bark of twigs brown; leaflets lanceolate to elliptic, 15-60

mm x 3-10 mm, the margins irregularly toothed or

ONS NELITINVES CIOLITTS conconncqenn0ci0600660068995665055050550000000 B. fagaroides

2' Bark of twigs reddish; leaflets mostly linear, 5—25 x 1—-2.5

mm, the margins entire or occasionally with a few small

IO) SYES Saco secoocseseccesoacosceqoonssccsedospdcnoacoe esa 500000 B. microphylla

Bursera fagaroides (Kunth) Engelm. var. elongata McVaugh &

Rzed. Torote; tooro, saa tooro (Yaqui). Small tree. Leaves present

during summer rainy season and quickly shed in September. Flow-

ers white, minute; early summer. Canyon slopes and open desert.

Distinguished from B. microphylla by its larger leaves with larger,

broader, and fewer leaflets. Starr 215.

Bursera laxiflora S. Watson. Torote prieto; chukui tooro (Yaqui).

Large shrub or small tree, the bark red-brown. Leaves drought

deciduous and fernlike, produced following rainfall at any season.

Flowers and fruits on long slender pendulous peduncles. Flowers

white, minute; August. Canyon bottom near entrance, slopes, and

open desert. F 85-843.

Bursera microphylla A. Gray. Torote; elephant tree, tooro, saa

tooro (Yaqui). Small tree or large shrub with fat semi-succulent

limbs and trunk; sap and leaves highly aromatic. Leaves appearing

at various seasons following rainfall. Flowers yellow-white,

minute; summer. Common in open desert and on rocky, arid

(especially south-facing) slopes. F 92-1060; 11978.

CACTACEAE—Cactus Family

1. Columnar cacti, the stems mostly >1.5 m and with conspicu-

ous ribs.

2. Stems and spines not conspicuously dimorphic, the spines

similar on juvenile (lower or sterile portion) and adult

(upper or fertile portion) stems; areoles bearing tufts of red-

brown glandular hairs, with an exudate producing dark red

to blackish encrustations on the spines .............. Stenocereus

2' Stems and spines markedly dimorphic, the juvenile and

adult stems markedly different (e.g., stem diameter, rib

numbers, distance between areoles, spine lengths and

morphology); areoles not producing dark exudate.

3. Stem ribs 6-8; sterile Guvenile) stem parts with short,

thick spines, the fertile (adult) stems parts with long,

slender, twisted and often flattened spines, the areoles

producing multiple flowers ...........0.0:::cee Lophocereus

3' Stem ribs 12-25; fertile (adult) stems spineless or spines

shorter than those of sterile (juvenile) stems and not

obscuring the stem surfaces, the areoles one-flowered.

4. Upper (fertile) growth with 19-25 ribs; areoles of adult

stems close but not coalesced and with bristly spines;

fruits spineless or nearly SO .............. eee Carnegiea

4' Upper (fertile) growth with 12-15 ribs; areoles of adult

stems coalesced, lacking spines or with short, stout

spines; fruits densely spiny or with dense feltlike hairs.

Pre Ca econo Soc EEE CREE EEEE oe RE oe CEEOL Pachycereus

1’ Not columnar cacti; stems <1.5 m, or if as long or longer then

constricted into many joints and without stem ribs; stem ribs

present or not.

5. Barrel cacti; stem thick and unbranched, >20 cm in

diameter; spines stout; flowers and fruits spineless and

ENDO KS sepeaeeedecaarpaccbes essen asc0a9aenonchnctandpbanconcoscosncsdob Ferocactus

5' Growth forms various, but not barrel cacti; stems <15 cm in

diameter; spines not stout; flowers and fruits spiny and

pubescent or not.

6. Chollas and prickly pears; stems constricted into joints or

pads; areoles with glochids (small spines deciduous at a

touch) in addition to larger, persistent spines ....... Opuntia

6' Not chollas or prickly pears; stems not constricted into

joints or pads; glochids none (if spines small, then not

readily deciduous).

7. Stems <2 cm in diameter, conspicuously grooved,

more than 20 times longer than wide; spines incon-

RIDE TONS, Te} THAIN). coodesseadnnosnossecnocoo9e900000g0080 Peniocereus

7' Stems >3 cm in diameter, not grooved, <6 times as

long as wide; spines conspicuous, mostly >8 mm.

8. Stems with ribs rather than tubercles, the spines

straight; floral tube and fruits spiny ..... Echinocereus

8' Stems with conspicuous tubercles rather than ribs,

each tubercle with a terminal spine-bearing areole,

the central spine(s) sometimes hooked or curved;

flowers and fruits without spines.......... Mammillaria

Carnegiea gigantea (Engelm.) Britton & Rose [Cereus giganteus

Engelm.]. Sahuaro; saguaro; sauwo (Yaqui). Giant columnar cac-

tus. Flowers white; early summer. Sparse, on south-facing slopes.

Echinocereus—Hedgehog cactus

NaS) ONES Et NEEISE S) C100) cecoposcoscogsocsossedcooce5cH5600005000000 E. engelmannii

JUS pinesmlESiemyorShorteneecscsseeescsesesteeeeeeees E. scopulorum

Echinocereus engelmannii (Engelm.) Riimpler subsp. llanuraen-

sis (J. Rutow) Felger, comb. nov. [Echinocereus nicholii (L. D.

Benson) B. D. Parfitt subsp. Manuraensis J. Rutow, Der Echino-

cereenfreund 8(3):61—70, 1995]. Guaymas hedgehog cactus. Plants

cespitose, the stems several to many, ca. 15-20 cm, ca. 5 cm in

diameter, often from short rhizomes. Spines moderately dense,

bicolored, dull yellow to brown, white, or gray, fading (or remain-

ing) gray with age, the central spines 4, the longer (lower) central

spine 3.0—5.8 cm, twisted or straight, flattened or terete, the other

spines terete. Flowers showy, 9.5 x 5—6 cm, the inner tepals ma-

genta; flowering spring and again in summer. Open, usually sparsely

vegetated rock slopes with shallow soil or exposed and often nearly

barren rock on various exposures. F 85-545.

The type locality for this subspecies is given as “Guaymas.” This

hedgehog cactus is widespread in the San Carlos region and through

the Sierra El Aguaje, on Cerro el Vigia at Guaymas, and also occurs

on Sierra Libre.

Allan Zimmerman (personal communication, 1996) counted the

chromosomes of plants from the Nacapule population and found

them tetraploid, aligning them with the E. engelmannii complex of

the southwestern United States and northwestern Mexico rather than

with E. nicholii (see Parfitt 1987). Subspecies //anuraensis further

shows affinity with the E. engelmannii complex by having dull gray-

ish, often bicolored spines becoming (or remaining) gray with age

and large showy flowers with bright deep magenta inner tepals. In

contrast, E. nicholii has uniformly yellow spines often turning black-

ish with age and smaller, less showy flowers with pale pink inner

tepals. Echinocereus nicholii occurs in southern Arizona and western

Sonora south to the Sierra Seri (opposite Isla Tiburon); I do not know

of it in the Sierra E] Aguaje or the Sierra Libre.

Echinocereus scopulorum Britton & Rose [E. pectinatus

(Scheidw.) Engelm. var. scopulorum (Britton & Rose) L.D.

Benson]. Sonoran rainbow cactus. Stems solitary, the spines dull-

colored, mostly 10-15 mm. Flowers large and showy, the perianth

The Flora of Canon de Nacapule: A Desert-Bounded Tropical Canyon near Guaymas, Sonora, Mexico 21

bright pink fading to magenta; April and July-August. Fairl

o © c c

common on steep mostly south-facing sparsely vegetated rock

slopes. F 95-63.

Ferocactus emoryi (Engelm.) Orcutt [F. covillei Britton & Rose].

Biznaga; barrel cactus; ono’e (Yaqui). Occasionally reaching 2 m

in height. Spine clusters with stout spines only. Flowers yellow;

August. Common on rocky slopes with various exposures and the

nearby open desert. The Nacapule-San Carlos population has

yellow flowers as in those from the Guaymas region southward,

rather than red flowers as found north of the Guaymas region.

Lophocereus schottii (Engelm.) Britton & Rose var. schottit.

Sinita; senita; museo (Yaqui). Small columnar cactus. Flowers

whitish to dull pink; warmer times of the year. Scattered on steep

canyon slopes, some even on shaded north-facing cliffs; common

at the canyon mouth and on the desert plain. Parfitt 3037 (ASU), n

= 11 (Pinkava et al. 1985).

The San Carlos—Guaymas region population, with 6-8 stem ribs,

is morphologically and geographically intermediate between the

northern var. schottii with thicker stems and 5-8 ribs and the south-

ern var. australis (K. Brandegee) Borg with thinner stems and 6-10

ribs (Felger and Lowe 1967, Lindsay 1963).

Mammillaria—Fishhook or pincushion cactus

1. Stems globose, as broad or broader than wide, the spines

straight or curved but not hooked; sap milky. ...... M. johnstonii

1’ Stems globose to taller than wide, the central spines hooked or

Sthaishtsaphwatenyiee en eeeon eee eee eee M. swinglei

Mammillaria johnstonii (Britton & Rose) Orcutt [M. johnstonii

var. sancarlosensis R. T. Craig; M. johnstonii var. guaymensis R.

T. Craig]. San Carlos pincushion cactus; chikul aaki, chikul hu’i

(Yaqui). Stems globose, often broader than tall, solitary or cluster-

ing, a few larger plants at least 30 x 50 cm with 16 or more stems.

Inner tepals cream to pink; summer. Rocky slopes with shallow

soil on various exposures. The spine lengths are highly variable.

Mamamnillaria swinglei (Britton & Rose) Boed. [M. inaiae R. T.

Craig]. Cabeza de viejo; fishhook cactus; chikul aaki, chikul hu’i

(Yaqui). Stems solitary or with a few branches, usually taller than

wide; central spine(s) may be hooked or straight, even on the same

plant. Some plants have straight spines only. Inner tepals white to

cream with a broad pale pink midstripe; various seasons but

mostly following rains during warmer weather. Rocky slopes with

various exposures, mostly on shallow soils, and nearby open

desert. F 95-62.

Opuntia—Chollas and prickly pears

1. Prickly pears, the stem segments (“pads”) flattened or

compressed; surfaces relatively flat, not tuberculate; spines

not sheathed .... ... O. gosseliniana

1’ Chollas, the stem segments (“joints”) more or less rounded in

cross-section (cylindroid), often tuberculate; spines with

papery sheaths at least when young.

2. Stems green all year; fruits proliferating in perennial

pendent chains of 3 or more fruits ..............00:00000 O. fulgida

2' Stems often purple-brown in winter and dry seasons; fruits

single, annual, not proliferating in pendent chains ................

Bare crap eR ERROR Sie ERS n erry erred ae O. versicolor

Opuntia fulgida Engelm. var. fulgida. Cholla; jumping cholla;

seve’e choa (Yaqui). Flowers rose-pink; summer. Fruits green and

fleshy. Locally rare; several widely scattered plants, <1 m, first

recorded in early 1995 on open desert between the spring and

canyon entrance and in arroyo below the canyon entrance. These

plants seem to have been brought into the area by cattle; the

species is common in nearby heavily grazed disturbed habitats in

the San Carlos—Guaymas region.

Opuntia gosseliniana F. A. C. Weber [O. violacea Engelm. var.

gosseliniana (F. A. C. Weber) L. D. Benson]. Duraznillo; purple

prickly pear; nakkaim, naavo (Yaqui). Cladodes (pads) turning

purplish during winter and early spring, probably in response to

relatively cool nights and drought; spines 5.5—8.0 cm. Flowers

bright yellow; March-April. Seedlings and juvenile plants with

long hairlike spines. Rocky slopes on both sides of the canyon and

arid slopes near the canyon entrance.

Opuntia versicolor Engelm. Siviri; staghorn cholla; sevii (Yaqui).

Often 1.5—2+ m with an upright trunk and main stems and spread-

ing branches. Flowering March-early April. Fruits fleshy, green-

ish yellow even when ripe, usually persistent until the following

year, often becoming enlarged and swollen, usually solitary.

Rarely in chains of two or three fruits but these not pendent.

Common in desert scrub near the canyon entrance. Plants in the

Guaymas region have flowers with inner tepals that are greenish

yellow with reddish brown tips. F 85-546.

Pachycereus pringlei (S. Watson) Britton & Rose. Cardoén,

sahueso. Giant columnar cactus, the juvenile portion of the stems

with long stout spines, the adult or fertile (upper) portion of stems

with coalesced areoles and spineless or with bristly spines only.

Flowers white, nocturnal, remaining open in daytime: spring.

Infrequent on south-facing slopes; more common elsewhere in the

region in arid, coastal habitats.

Peniocereus striatus (Brandegee) Buxbaum [Cereus striatus

Brandegee; Neoevansia striata (Brandegee) Sanchez-Me}.;

Wilcoxia striata (Brandegee) Britton & Rose; Cereus diguetii K.

Weber: Wilcoxia diguetii (K. Weber) Diguet & Guillaumin]. Saca-

matraca; noono (Yaqui). Stems pencil thin, often 1-2 m, growing

through shrubs such as Citharexylum or Lycium and seemingly

mimicking their nurse-plant stems; plants with clusters of

potatolike tuberous roots. Flowers nocturnal, white; summer.

Fruits ripening in late summer or early fall. Fairly common near

the canyon entrance and on the nearby open desert.

Stenocereus thurberi (Engelm.) Buxbaum [Lemaireocereus

thurberi (Engelm.) Britton & Rose]. Pitahaya dulce; organ-pipe

cactus; aaki (Yaqui). Multiple-stemmed columnar cactus. Flowers

nocturnal, the interior white; hot weather, mostly in early summer.

Fruits red, juicy, sweet, and edible, ripe during summer. Canyon

slopes, most numerous on south-facing slopes, and also common in

the nearby desert. Parfitt 3035 (ASU), n= 11 (Pinkava et al. 1985).

CAPPARACEAE—Caper Family

1. Herbaceous annuals; leaves with 3—5 leaflets ............... Cleome

1’ Woody shrubs or trees; leaves simple .............. Forchhammeria

Cleome tenuis S. Watson. Hot-weather ephemeral with slender,

upright stems; flowers inconspicuous. Canyon bottom and nearby

open desert. F 85-1203.

Forchhammeria watsonii Rose. Jito; hi’ito (Yaqui). Unarmed

tree 5—6 m with a single thick smooth trunk and dense essentially

evergreen crown; leaves of young plants narrowly linear, those of

the mature tree much broader. Dioecious. Flowers small, the male

flowers yellow, the female flowers maroon; mass flowering mostly

March-April. Scattered along the canyon bottom, more common

in the nearby open desert. Van Devender 84-243; Wiseman 77-64.

CHENOPODIACEAE—Goosetoot Family

Chenopodium—Goosefoot

1. Herbage green or green with reddish tinges; seed margins

ACWUIO resect ai ctaccane seus tecas vac Unscs teeta vest out das oseeeten rn coe eeeaee C. murale

1' Herbage grayish (mealy); seed margins acute to obtuse............

DEE SOE OAM ee OR Rare ging sehen sree ans tees C. neomexicanum

*Chenopodium murale L. Chual; netleaf goosefoot; chuuhi

(Yaqui). Winter-spring ephemeral. Heavily grazed area at

Nacapule Spring; not seen prior to 1995. F 95-105.

Chenopodium neomexicanum Standl. Choali (Yaqui). Annual,

germinating in spring and maturing during summer. The plants,

especially when mature, stink like dead fish but the tender young

herbage is eaten locally as greens (“quelite, se come”). Common

along the canyon bottom, especially in areas frequented by cattle.

F 85-266, 85-1329.

“ ~ CONVOLVULACEAE—Morning-Glory Family

1. Parasites; stems vining, orange, and leafless ............... Cuscuta

1' Not parasites; stems vining or not, not orange; leaves present

although sometimes deciduous.

2. Perennials; stems not vining; corollas pale blue, <1 cm wide

See rss lent tedes Nes Sedans eA ae aati recta Sateenes tern eee tas c es Evolvulus

2' Annuals; stems vining; corollas variously colored, not pale

bluewatileas tallcmbwicl epeeesrescesatsenacescsstescestessase Ipomoea

Cuscuta—Dodder

1. On shrubs; perianth segments obtuse ................+. C. americana

1’ On herbaceous annuals or perennials; perianth segments acute.

2. Calyx lobes lanceolate ................ eee C. desmouliniana

2' Calyx lobes deltoid to ovate ............ cece C. umbellata

Cuscuta americana L. Probably annual; on woody shrubs includ-

ing Colubrina viridis, Sebastiania bilocularis, and Vallesia

laciniata. Nonseasonal in growth and flowering response. Stems

thicker than those of the ephemeral species. Flowers white. Can-

yon bottom. F 4087, 84-618.

Cuscuta desmouliniana Yunck. Warm-weather ephemeral on Eu-

phorbia polycarpa. Flowers white. Terrace above arroyo at can-

yon mouth. Burgess 6949.

Cuscuta umbellata Kunth. Warm-weather ephemeral, sometimes

persisting through winter, on various herbaceous plants, espe-

cially Boerhavia spp., Bouteloua aristidoides, Euphorbia

polycarpa, and Kallstroemia grandiflora. Flowers white. Open

habitats at canyon entrance and the open desert. F 85-578.

Evolvulus alsinoides (L.) L. var. angustifolia Torr. [E. alsinoides

var. acapulcensis (Willd.) Ooststr.]. Small herbaceous perennial.

Flowers open in the morning and fade with daytime heat; nonsea-

sonal with sufficient soil moisture. Canyon bottom in open habi-

tats, north- and south-facing canyon slopes, and nearby desert,

especially along washes. F 84-106, 85-1187.

Ipomoea—Morning-glory

1. Leaves divided into narrow palmately arranged segments ........

Heil errr SB le PE ME Sr Eh ee Mie aS Soa et gd eaee santa ce ene ve I. leptotoma

1’ Leaves simple, entire to broadly lobed.

2. Sepals glabrous, the lobes linear-subulate; corollas

Salivatonmy bri ohtine dee eesssteescoscenstensceesceecrces I. cristulata

2' Sepals with large, coarse hairs, especially on the tube, the

lobes attenuate-tipped; corollas rotate (opening wide),

bluish or lavender, generally with a white base. /. hederacea

Ipomoea cristulata Hallier f. Warm-weather ephemeral; small

vine, delicate to sometimes robust. Flowers often open all day.

Occasional in the canyon bottom, usually near water in the vicin-

ity of Ficus insipida. F 4085, 85-1310.

Ipomoea hederacea Jacq. Trompillo; morning-glory. Warm-

weather annual vine, often rank. Flowers open in the early morn-

22 Richard S. Felger

ing, fade with daytime heat. Infrequent along the canyon bottom.

F 4086, 85-1317.

Ipomoea leptotoma Torr. Warm-weather ephemeral vine. Corollas

lavender, open in the early morning, fade with daytime heat.

Canyon bottom and open desert. F 4086, 85-1185.

CUCURBITACEAE—Gourd Family

1. Summer-growing perennials from a thick caudex; tendrils

simple; fruits fleshy, ovoid or broadly ellipsoid, and smooth.

wu Frwdadocosetescesgseeeasdees!iccseae ots Sedsus sat cuts Oatae seats ee ees ceeee Ibervillea

1‘ Cool-season annuals without a caudex; tendrils usually forked;

fruits dry when mature, globose, mostly spiny (echinate) .........

Poche oa cuit et ancien io ia Nate che See oe PE EE ONE EES MOL GUE ee Vaseyanthus

Ibervillea sonorae (S. Watson) Greene [Maximowiczia sonorae S.

Watson; Ibervillea sonorae var. peninsulare Brandegee,; I.

insularis (Brandegee) Wiggins]. Giierequi; cow-pie plant; kau

chaani (Yaqui). Plant with a large swollen above-ground caudex

often resembling a large cow dropping. Leafy stems appearing

with summer rains and quickly deciduous at the end of the rainy

season. Flowers dull yellow; summer. Fruits yellow to orange-red

when fully ripe; late summer. Common in the open desert and

scattered on canyon slopes. F 84-132, 85-1322.

Vaseyanthus insularis (S. Watson) Rose. Vine growing luxuri-

antly with fall to spring rains and dying in late spring, often

carpeting otherwise barren rock slopes and festooning trees and

shrubs in green curtains. Flowers small, white. F 85-250; Daniel

1996 (ASU, n = 13); Parfitt 3023 (ASU).

EUPHORBIACEAE—Spurge Family

1. Stems thick, succulent, terete, and green, without spur

branches, the stem tips sharp-pointed; leaves few and quickly

GIORGOS seccccssoaceacocscoscacnecooasocsncsa0ndEnGens050 Euphorbia ceroderma

1’ Stems not as above, not succulent or if so then with spur

branches; leaves many.

2. Plants usually scandent or vining, mostly herbaceous.

3. Hairs on herbage not stinging; leaves often 5—8.5 cm,

palmately 3-lobed ....................::.:csssseeseseesess Dalechampia

3' Herbage with stinging hairs; leaves mostly 1.5—5 cm,

ovate to elliptic, not lobed ................ceceeeeeeeeseeees Tragia

2' Plants not scandent or vining; herbaceous to shrubby.

4. Sap milky; leaves opposite; flowers enclosed in a cuplike

involucre (cyathium) of gland-bearing united bracts, the

whole structure simulating a bisexual flower; perianth

none, the staminate flower consisting of a single,

pediceled stamen, the pistillate flower of a single

JOSOOSSCUCNTENAY, <tratocosoonsocasoooeeoosacssodeocebssoac0ac00000 Euphorbia

4' Sap milky or not; leaves alternate; flowers not enclosed

in a cyathium; staminate flowers with a perianth.

5. Annual and perennial herbs, often <1 m, with two-

armed (Malpighian) hairs ............:.::c:ceceeeeeeees Ditaxis

5' Shrubs; glabrous or pubescent but the hairs not two-

armed.

6. Older leaves turning orange before falling; pubes-

Gencevolistellatejhatnsjesseeresesesnesaemesere ene Croton

6’ Older leaves not turning orange; glabrous or

pubescent with simple hairs.

7. Sap of copious milky latex; glabrous. Sebastiania

7' Sap not milky; glabrous or pubescent.

8. Plants with conspicuous glandular and

nonglandular hairs .............0.ccceeee Acalypha

8’ Glabrous or the hairs inconspicuous, not

glandular.

The Flora of Canon de Nacapule: A Desert-Bounded Tropical Canyon near Guaymas, Sonora, Mexico 23

9. Hardwood shrubs, not at all succulent, the

stems rather rigid; sap not watery ........ Adelia

9' Softwood shrubs, semi-succulent, the stems

flexible; sap watery, clear, or colored.............

RE CpALERE Toe cce CORCE LESS ARCO Cnor Rac ORE Jatropha

Acalypha californica Benth. [A. pringlei S. Watson; A. vagans

Cav. sensu Wiggins (1964) but not as to the type. See Levin (1994)

and Steinmann and Felger (1997)]. Copperleaf. Shrub often 1.5—

1.8 m; leaves gradually drought deciduous. Mostly along the

canyon bottom and on north-facing slopes. Flowering at various

seasons. F 84-/45; Starr 202; Van Devender 28 Dec 1982.

Adelia virgata Brandegee. Shrub 2—3+ m. Leaves quickly drought

deciduous. Flowers green, inconspicuous. Canyon bottom at en-

trance. F 92-1032.

Croton sonorae Torr. Mariola. Woody shrub 1.0-1.5 m; tardily

drought deciduous, the leaves turning orange before falling. Stami-

nate flowers white; August. Canyon bottom and slopes; widespread

on nearby desert plains and rocky slopes. F 84-611; Warren 18 Aug

1975.

Dalechampia scandens L. Facultative ephemeral, in dry years as

small as 10-30 cm, nonvining, and producing seeds; during wet

years becoming a short-lived scandent perennial with a semi-

woody base. Canyon bottom and mostly shaded north-facing

slopes. F 84-602, 85-848; Yatskievych 82-151.

Throughout its extensive range in the American tropics and sub-

tropics this species is usually a large scandent shrub or vine, rarely a

perennial herb. The ephemeral phase is unusual. This species enters

the Sonoran Desert only in several riparian canyons in the Sierra El

Aguaje and Sierra Libre.

Ditaxis

1. Plants subshrubby; stems mostly erect and straight; staminate

petals united to the staminal column at base, appearing to arise

above the glands; style branches sometimes dilated and

Hlattenedkatitheyla pexesnsese ste se hans. ceneee resets D. lanceolata

1’ Plants herbaceous; stems mostly ascending to spreading, the

main axis sometimes erect but the branches spreading and

seldom straight; staminate petals free from the staminal

column, appearing to arise between and alternating with the

glands; style branches terete at the apex ......... D. neomexicana

Ditaxis lanceolata (Benth.) Pax & K. Hoffm. [Argythamnia

lanceolata (Benth.) Mill. Arg.; Ditaxis palmeri (S. Watson) Pax &

K. Hoffm.]. Suffrutescent perennial to 1+ m, sometimes flowering

in the first season; leaves often silvery-pubescent, tardily drought

deciduous; nonseasonal. Canyon bottom, slopes, and nearby

desert. F 84-134, 85-567.

Plants in well-watered shaded areas along the canyon bottom tend

to have larger, broader, and green rather than silvery leaves. Ditaxis

palmeri, described from Guaymas, is apparently based on such plants

(Steinmann and Felger 1997).

Ditaxis neomexicana (Mill. Arg.) A. Heller [Argythamnia neo-

mexicana Mill. Arg.; A. gracilis Brandegee; Ditaxis gracilis Rose

& Standl.]. Nonseasonal ephemeral to short-lived perennial. Open

slopes, canyon entrance, and adjacent desert. Argythamnia graci-

lis and Ditaxis gracilis, each independently based on separate

collections, appear to be nothing more than robust plants growing

under highly favorable conditions during the summer rainy season

(Steinmann and Felger 1997). F 85-836, 85-575.

Euphorbia

1. Shrubs.

2. Stems succulent, with few, quickly deciduous leaves ...........

ES EIT 6 ADE ec Ie USO EDS O82 E. ceroderma

2’ Stems leafy and not succulent E. tomentulosa

1’ Annual or perennial herbs.

3. Cyathia in dense subcapitate leafless cymose clusters ..........

aU IOS LORE Shei eee nee -o AEE E. capitellata

3' Cyathia solitary in the axils of leafy shoots.

4. Herbage with appressed hairs only............. E. pediculifera

4' Herbage glabrous or with at least some spreading hairs.

5. Appendages rounded to broadly lobed or absent ...........

Neveu teseiuSnascncaueaun deat eteaediwes cdc cath are rneunnen aaa E. polycarpa

5' Appendages divided into triangular, pointed segments,

the cyathia thus appearing “star-shaped.” .... E. setiloba

Euphorbia capitellata Engelm. [Chamaesyce capitellata

(Engelm.) Millsp.]. Golondrina; koapa’im (Yaqui). Herbaceous

perennial, often flowering in the first season. Petaloid appendages

white. Flowering nearly all year except during extended drought.

Canyon bottom and near canyon entrance, mostly in gravelly

washes, and dry rocky slopes and nearby arroyo beds. F 84-569.

Euphorbia ceroderma |. M. Johnst. Shrub 1.0-1.5 m, forming

dense clumps, the stems green, rigid, and succulent, each with

several or more spreading-ascending branches, the tips drying to

form a rigid thorn. Leaves very sparse, very quickly deciduous,

and seldom seen, often 9-11 mm, semi-succulent, sparsely pu-

berulent with short appressed white hairs, essentially sessile with

a thick petiole <1 mm, the blades narrowly linear-lanceolate, the

apex acute. Reproductive with summer rains.

Exposed steep north and south canyon slopes and rugged slopes

high above the canyon. F 92-1048, 94-859. This is one of the few

succulent “cactoid” euphorbias in the Sonoran Desert (see Steinmann

and Felger 1997).

Euphorbia pediculifera Engelm. var. linearifolia S. Watson.

Golondrina; louse spurge; koapa’im (Yaqui). Nonseasonal ephem-

eral or (mostly) short-lived perennial. Appendages white, fading

pink. Widespread, especially in gravelly soil along the canyon

bottom, rocky slopes, and the open desert. This subspecies is

endemic to the Guaymas region. Daniel 2003 (ASU); F 85-1202;

Van Devender 84-241.

Euphorbia polycarpa Benth. [Chamaesyce polycarpa (Benth.)

Millsp.]. Golondrina; desert spurge; koapa’im (Yaqui). Nonsea-

sonal ephemeral to small perennial herb. Appendages white, in

drought sometimes minute or essentially absent. Widespread;

slopes, gravelly arroyo bed of canyon bottom, and especially

common at the canyon entrance and on the open desert. F 11975,

85-1183A.

Euphorbia setiloba Engelm. [Chamaesyce setiloba (Engelm.)

Millsp.]. Golondrina; fringed spurge. Nonseasonal ephemeral.

Appendages white to pink, divided into toothlike segments form-

ing a starlike pattern. Gravelly soils of open areas along canyon

bottom and in open desert. F 1/866, 85-1330

Euphorbia tomentulosa S. Watson [Chamaesyce tomentulosa (S.

Watson) Millsp.]. Shrub 1-1.5 m; leaves tardily drought decidu-

ous. Appendages white; nonseasonal. Canyon slopes, especially

the more arid habitats, open rocky areas along the canyon bottom,

and on nearby desert hills. F 94-862; Steinmann 15 Aug 1992.

Jatropha

1. Bark papery and peeling; leaves conspicuously petioled, the

blades cordate, about as wide as long, mostly >4 cm................

1’ Bark not papery and peeling; leaves sessile to subsessile, or

the long-shoot leaves petioled, the blades spatulate, about

twice as long as wide, mostly <2 CM........0..0::eeee J. cuneata

Jatropha cordata (Ortega) Miill. Arg. Copalillo, torote papelillo;

kau sapo (Yaqui). Slender, erect, Bursera-like shrub 2—3 m; bark

papery and peeling in dry seasons. Leaves present only during

24 Richard S. Felger

summer rainy season and quickly deciduous after the rains cease

in September. Flowers white to pink; July-August. Steep slopes

on both sides of the canyon. Farther south and east in Sonora J.

cordata is a small tree. F 84-119, 85-858.

Jatropha cuneata Wiggins & Rollins. Sangrengado; limberbush.

Multiple-stemmed shrub |.5—2.5 m; lower stems and roots oozing

blood-like sap when cut (hence the common name); roots thick,

almost tuberous. Short shoots producing leaves after rains at al-

most any time of the year, bearing smaller, sessile, entire, and

quickly drought-deciduous leaves, the long shoots developing

with summer-fall rains and bearing larger, petioled, and lobed

leaves. Flowers white; summer rainy season. South-facing slopes,

the canyon entrance, and nearby desert. F 92-1041, 94-863.

Sebastiania bilocularis S. Watson [Sapium biloculare (S. Watson)

Pax]. Hierba de la flecha; Arizona jumping bean; hoyo kuta (Yaqui).

Shrub 3-4 m. Staminate flowers yellow; various seasons including

August. Nearly evergreen along the canyon floor, tardily drought

deciduous on slopes and the open desert. F 85-854; Starr 2/1.

Tragia jonesii Radcl.-Sm. [T. scandens MLE. Jones, not T. scandens

L.; T. amblyodonta (Mill. Arg.) Pax & K. Hoffm., sensu Wiggins

1964]. Quemador; noseburn; nata’e (Yaqui). Vining perennial with

slender stems and mildly stinging hairs, the leaves drought decidu-

ous. Usually beneath shrubs in the canyon bottom, on north-facing

slopes, and in nearby desert habitats. F 85-550, F 95-17.

This species ranges from northwestern Sonora to southern

Mexico and also occurs in Baja California Sur. It has been treated as

T. amblyodonta (Mull. Arg.) Pax & K. Hoffm. but represents a quite

different species (Steinmann and Felger 1997).

FABACEAE (LEGUMINOSAE)—Legume Family

1. Stems vining.

2. Annuals; flowers pink ...........ceeesessceseeseeeeeeeeeeeeee Phaseolus

2' Perennials; flowers yellow or red-brown.

3. Leaves with 5 leaflets; pods indehiscent, one-seeded .......

3' Leaves with 3 leaflets; pods dehiscent, multiple-seeded.

4. Flowers dark red-brown; seeds brown .....Macroptilium

4' Flowers yellow; seeds red and black ........... Rhynchosia

1’ Stems not vining.

5. Trees or woody shrubs, mostly >1 m (ambiguous cases key

out in both places).

6. Bark green, at least on upper limbs; flowers caesalpinioid.

SESE HOLES SES poar pe coarE RE CER eo EES OS SoCSOR REECE SOC ShoSC Parkinsonia

6' Bark not green (except sometimes on first or second

year’s growth); flowers various.

7. Leaves once pinnate; flowers caesalpinioid or

papilionoid.

8. Trunk and limbs fluted, the bark smooth; leaves

even-pinnate; leaflets 4-8, broadest above middle,

with conspicuous lateral veins; flowers caesal-

jovvaVKONGl, SHEIKGNYY <cecbeaceaseesesseotsscsoubcoooudes Haematoxylum

8' Trunk and limbs not fluted, rounded in cross-section,

the bark rough on the trunk and older limbs; leaves

odd-pinnate or sometimes even-pinnate; leaflets 6—

19, mostly broadest at or below the middle, the

lateral veins inconspicuous; flower papilionoid,

yellow or not.

9. Pods papery and inflated; flowers bright yellow.

Abs crctarmaten al duet le Sues Ventnah) <acnereel Seon ta aes Diphysa

9' Pods not papery and inflated; flowers not yellow.

10. Leaflet tips with a conspicuous mucronate pro-

jection; pods glandular ..... Coursetia glandulosa

10’ Leaflets not apiculate, the tips rounded, blunt,

or notched; pods not glandular.

11. Trees or large shrubs, with a well-developed

thick trunk and shredding bark; branches

with prominent spines at bases of at least

GOWNS NEANTES ccocasssdoocacccoosdneccsenstoosesse60080 Olneya

11'Small shrubs, scarcely woody, the bark not

shredding; unarmed.

12. Pods one-seeded; corollas bright purple,

about as long to scarcely longer than the

calyx; midrib of calyx lobes extending into.

awnlike plumose bristles................... Dalea

12' Pods multiple-seeded; corollas salmon-

orange, longer than the calyx; calyx lobe

FAKOXO EDVSG cconqoqangesecesocesecan668009000 Indigofera

7' Leaves twice pinnate; flowers caesalpinioid or

mimosoid.

13. Flowers caesalpinioid; leafstalk glands none.

14. Unarmed; leaflets broadest at or below middle,

Mot notched at tiph.-..t..cscccccsess-eenneeeeses Caesalpinia

14' Armed with stipular spines; leaflets broadest above

middle, usually notched at the tip .... Haematoxylum

13’ Flowers mimosoid; leafstalks often with craterform

gland(s).

15. Pods indehiscent.

16. Leaves with 2-4 pairs of pinnae; flowers in

dense rounded heads; stamens numerous ...........

aetees : Acacia farnesiana

16' Leaves with one pair of pinnae; flowers in

cylindrical racemes; stamens 10.......... Prosopis

15' Pods dehiscent.

17. Plants unarmed.

18. Leaves with one (sometimes two) pair(s) of

pinnae ... weve Acacia willardiana

18’ Leaves usually with three or more pairs of

pinnae.

19. Large shrubs or small trees; stipules leafy

(often soon deciduous); valves of pods

separating from a conspicuous rim.............

.. Lysiloma

19’ Small shrubs; stipules not leafy; valves of

pods not separating from the rim.

20. Stamens 10 or fewer; valves of pods

partially to fully separating but not

elastically and remaining straight...........

weaedtetee Sind cate tas chad susasdaeedee Desmanthus

20' Stamens numerous; valves of pods

separating elastically and curling back.

21. Stipules subulate, firm; leaflets

rather firm and thickish; flowers

buishtined perce eee eres Calliandra

21' Stipules ovate, not firm; leaflets thin,

not firm; flowers cream-white ............

Sb cups detecevaee eaten ones Zapoteca

17’ At least some branches conspicuously armed.

22. Spines straight, acicular to flattened or boat-

shaped. Acacia cochliacantha and A. pringlei

22' Spines curved (with a slight hook).

23. Shrubs; spines (prickles) internodal;

flowers pink-purple; pods to 5 cm,

breaking into one-seeded segments ............

ae Mimosa

23' Small trees; spines nodal; flowers white;

pods 5-10 cm, not separating into

segments .....

Havardia

5' Herbaceous annuals and perennials, not woody or scarcely so.

24. Leaves simple (unifoliolate) ................ Sphinctospermum

24' Leaves with three or more leaflets.

The Flora of Canon de Nacapule: A Desert-Bounded Tropical Canyon near Guaymas, Sonora, Mexico

25. Flowers caesalpinioid; leaves even-pinnate; anthers

larceswithiterminallporesieessscssstettecre eee eee Senna

25' Flowers papilionoid; leaves odd-pinnate; anthers

small, opening longitudinally, without pores.

26. Leaflets 9-23; herbage gland-dotted; pods 1.8—2.5 mm,

indehiscent, one-seeded; flowers dark blue ....... Marina

26' Leaflets three or five; herbage not gland-dotted;

pods >8 mm, dehiscent or breaking into segments,

with more than two seeds; flowers not dark blue.

27. Delicate hot-weather ephemerals with small

curved “hold-fast” hairs; pods resembling a series

of cut-outs, the segments triangular to four-

Conneredionrounded pee se weet: Desmodium

27' Winter—spring ephemerals, perennials, or robust

annuals, the hairs straight; pods more or less

entire (not “cut-out”).

28. Delicate winter—spring ephemerals; pods to

IBaykey sa tecerecerecppercrte ere cree one nosere ers Astragalus

28’ Rather robust annuals or perennials; pods at

least 3 cm.

29. Pods 5—8 cm, linear, conspicuously septate

between seeds; leaflets broadly elliptic to

OV ALC ease ee ay eeehes Coursetia caribaea

29' Pods 3—4.5 cm, linear-falcate, not septate;

leaflets wineateersscseese seco Tephrosia

Acacia

1. Unarmed; bark papery and peeling; glabrous or essentially so;

petioles long, slender, and straplike ................... A. willardiana

1’ Armed with stipular spines at least on some branches; bark not

papery and peeling; variously pubescent; petioles not as

above.

2. Leaves with 7 to many pairs of pinnae; spines flattened or

the larger ones boat-shaped ... .. A. cochliacantha

2' Leaves with 1-6 pairs of pinnae; spines acicular.

3. Leaves with 24 pairs of pinnae, the leaflets 1-7 mm;

pods pulpy (with mesocarp), indehiscent, dark brown to

blackish, not constricted between seeds ....... A. farnesiana

3’ Leaves with one pair of pinnae, the larger leaflets 7-45

mm; pods dry, tardily dehiscent, red-brown, slender,

constricted between\Seeds\een senses sereeereeeees A. pringlei

Acacia cochliacantha Willd. [A. cymbispina Sprague & Riley].

Chirahui; boat-spine acacia; koowi tami (Yaqui). Shrub 3+ m;

drought deciduous. Flowers yellow-orange; June—September (—

November). Occasional in the canyon bottom near the entrance

and most common at the spring; apparently a recent invader

associated with cattle grazing. F 95-33, 95-57.

Acacia farnesiana (L.) Willd. [A. minuta (M. E. Jones) R. M.

Beauch. subsp. densiflora (Small) R. M. Beauch.; A. smallii Isely].

Huisache, vinorama; sweet acacia; kuka (Yaqui). Shrub to 4 m;

ultimately partially to fully winter deciduous. Flowers bright yel-

low-orange, sweet scented; December—March. Canyon entrance,

not common, and rare elsewhere along the canyon bottom and at

the spring. The Nacapule huisaches were seedlings and young

plants when first observed. They occur in areas of heavy cattle

grazing and disturbance, and seem to be recent invaders. In the

San Carlos—Guaymas region the species thrives in disturbed habi-

tats. Daniel 1985 (ASU); F 92-1044.

Acacia pringlei Rose subsp. californica (Brandegee) Lee, Seigler

& Ebinger [A. californica Brandegee]. Chicorai (Yaqui). Shrub 3-

4m; mostly evergreen. Flowers pale yellow; (March—) May—June.

Canyon bottom and steep east-facing rock slope below cliffs at the

southeast side of the canyon entrance. Recorded 28 December

1985 (observation). This acacia is distinctive owing to its striking,

dark green foliage contrasting with the large white spines. The

leaflets are the largest of the Sonoran acacias.

Acacia willardiana Rose. Palo blanco; nawi'o (Yaqui). Slender

wispy tree 3—5+ m; bark white, exfoliating in sheets during dry

seasons; leaflets and then the pinnae drought deciduous, leaving

the leafstalk to function as a phyllode—unique among New World

acacias. Flowers pale yellow; February—May and October. Arid

canyon slopes, cliffs, and the nearby desert. F 85-56/.

Astragalus nuttallianus DC. var. imperfectus (Rydb.) Barneby.

Small-flowered milk-vetch. Delicate, winter—spring ephemeral.

Flowers bluish, selfing and semi-cleistogamous. This is the small-

est Astragalus species in the Sonoran Desert. Canyon entrance and

open desert. F 95-1.

Caesalpinia

1. Leaflets elliptic to oblong, to 6 mm wide; pods explosively

GEMISCEM tye ee Recess ocean cd rr essa aaet ete C. palmeri

1' Leaflets nearly orbicular, ca. 5—20 mm wide: pods indehiscent.

...C. pumila

Caesalpinia palmeri S. Watson. Palo piojo; kume’a ouwo (Yaqui).

Shrub with conspicuous lenticels (said to resemble piojos, or lice,

hence the common name); tardily drought deciduous. Flowers

bright yellow, the sepals fading to red; warmer months except

during severe drought. South-facing canyon slopes, dry habitats at

the canyon entrance, and the open desert. F 85-584; Martin 12

Mar 1977.

Caesalpinia pumila (Britton & Rose) F. J. Herm. Small shrub;

tardily drought deciduous. Flowers yellow; summer. Open desert

near the canyon and occasionally on east-facing slopes near can-

yon mouth. F 85-87/B.

Calliandra californica Benth. Tabardillo; Baja California fairy

duster. Shrub 1.0—1.5 m; tardily drought deciduous. Flowers bright

red and showy; at least March and August. North- and northeast-

facing slopes and occasional in the nearby desert. Burgess 6533;

F 92-1039.

Coursetia

1. Suffrutescent perennials........

ImWoodyishrubSyesessrencercees

C. caribaea

.... C. glandulosa

Coursetia caribaea (Jacq.) Lavin var. caribaea [Cracca caribaea

(Jacq.) Benth.; C. caribaea var. edwardsii (A. Gray) Hassl.; C.

edwardsii A. Gray; C. brandegeei Rydb.; Benthamantha edwardsii

(A. Gray) Rose]. Stems to ca. 1 m; growing and flowering during hot-

weather rains, the fruits ripen in October; plant leafless and dormant

at other seasons. Flowers with a white keel and pink banner with red

streaks on the back. Common understory plant in the canyon bottom

and on densely vegetated north-facing slopes. F 84-138, 84-574.

Coursetia glandulosa A. Gray. Sdmota; saamo (Yaqui). Multiple-

stemmed shrub to 4 m; leaves unfolding in spring after flowering

except in severe drought, the foliage luxuriant with leaves and

leaflets largest during the summer-fall rainy season, smaller and

gradually deciduous during fall and winter. Flowers pale yellow

and white with pink to red tinges; spring. Canyon bottom, north

and south slopes, canyon entrance, and nearby desert slopes.

Stems sometimes encrusted with orange lac produced by the ant-

tended scale insect Tachardiella. F 85-256.

Dalea pulchra Gentry. Dense intricately branched shrub 0.5—1.3

m, the stems slender and rigid. Leaves silvery gray pubescent,

tardily drought deciduous. Flowers dark magenta-purple with a

large yellow spot on the banner, attracting large numbers of hon-

eybees; spring. Mostly on west- and south-facing rock faces but

also on other exposures. F 85-543. Also in the nearby hills and

canyon at El Baviso (between Nacapule and San Carlos) and at

26 Richard S. Felger

Las Barajitas. This species is absent across most of the Sonoran

Desert but widepread in mountains to the east.

Desmanthus covillei (Britton & Rose) Wiggins & B. L. Turner [D.

subulatus (Britton & Rose) B. L. Turner; D. palmeri (Britton &

Rose) B. L. Turner]. Site’epoa (Yaqui). Slender shrub often 1.5 m,

with delicate unarmed stems and filmy drought-deciduous foliage.

Growing and flowering mostly with summer rains. Flowers white.

Scattered along the canyon bottom, more common on mostly

north-facing slopes high above the canyon. F 4089, 84-133.

Desmodium procumbens (Mill.) Hitchc. var. procumbens. Tick

clover. Summer-—fall ephemeral with trifoliolate leaves. Flowers

pink, minute. Pods slender, resembling a series of cut-outs, the

segments triangular to four-cornered or rounded and with minute

hooked hairs. Canyon bottom and north-facing slopes, mostly

shaded beneath shrubs and trees. This species, widespread in the

American tropics as well as in temperate and montane habitats,

barely enters the Sonoran Desert; this is the northernmost popula-

tion along the Sonora coast. F 84-96, 85-1304.

Some of the Nacapule specimens show characters of both this

species and D. scopulorum S. Watson, which may be conspecific.

Furthermore, D. procumbens var. procumbens and var. exiguum (A.

Gray) Schubert are probably not distinct taxa.

Diphysa occidentalis Rose. Giiiloche. Shrub or small tree to ca. 4

m; gradually drought deciduous. Flowers bright yellow; summer

rainy season, November—April depending on rains. Pods inflated,

thin-walled and papery. North- and south-facing canyon slopes. F

85-851; Starr 201.

Haematoxylum brasiletto H. Karst. Brasil; huchahko (Yaqui).

Shrub with fluted hardwood stems and red heartwood, the nodes

often with a single spine; gradually drought deciduous. Flowers

bright yellow; nonseasonal. Canyon bottom, north and south

slopes, and the open desert. Starr 206.

Havardia sonorae (S. Watson) Britton & Rose [Pithecellobium

sonorae §. Watson]. Jécono; Sonoran ebony; wokohna (Yaqui).

Multiple-trunked tree or large shrub to 6+ m; tardily drought

deciduous. Flowers white; summer. Pods ripen in November.

Along a small arroyo running northward from near the canyon

entrance. F 94-850.

Indigofera jamaicensis Spreng. Suffrutescent perennial often |

m; drought deciduous. Corollas dark salmon-pink; nonseasonal.

Mostly on slopes, with various exposures. F 85-558.

Lysiloma divaricatum (Jacq.) J. F. Macbr. [L. microphyllum

Benth.]. Mauto; vamyo (Yaqui). Large shrub or small tree 4—6 m.

New growth in early summer; drought deciduous, the leaves shed

mostly in early fall. Flowers cream-white; April-May. Pods ripen-

ing late summer—October. Canyon bottom and slopes, especially

north-facing, and along arroyos in the nearby desert. Phillips 75-

145; Starr 24.

Macroptilium atropurpureum (DC.) Urb. [Phaseolus atropur-

pureus DC.]. Perennial, growing and flowering mostly during

summer rainy season. Flowers dark red-brown. North-facing

slopes and shaded canyon bottom among boulders and leaf litter

along the dry streambed. F 92-1023.

Marina parryi (Torr. & A. Gray ex A. Gray) Barneby [Dalea parryi

Torr. & A. Gray ex A. Gray]. Nonseasonal ephemeral, mostly in

spring; occasionally a short-lived perennial. Flowers blue. Open

habitats: arroyo bed near the canyon mouth, open desert, and south-

facing slopes. F 95-109.

Mimosa distachya Cav. var. laxiflora (Benth.) Barneby [M.

laxiflora Benth.]. Shrub; drought deciduous. Flowers pink, fad-

ing to white; various seasons. Dry habitats, mostly near the

canyon entrance, south-facing slopes, and the open desert. F 84-

610, 85-842.

Nissolia schottii (Torr.) A. Gray. Vine climbing through shrubs;

gradually drought deciduous. Flowers yellow; summer rainy sea-

son and sometimes at other seasons. Canyon bottom, north-facing

slopes, and nearby open desert. F 85-874, 95-21.

Olneya tesota A. Gray. Palo fierro; desert ironwood; ehea (Yaqui).

A grove of large shrubs and small trees on the steep south-facing

slope in the mid-portion of the canyon; common on nearby slopes

and the open desert. Flowers pink; late spring. Fruits ripening just

before the onset of summer rains. F 92-1026.

Parkinsonia microphylla Torr. |Cercidium microphyllum (Torr.)

Rose & I. M. Johnst.]. Palo verde; foothills palo verde; wo’i voa’am

(Yaqui). Small tree or large shrub; drought deciduous. Flowers pale

yellow and white; mass flowering in spring. Arid habitats, especially

south-facing slopes and the open desert. F 92-1054.

Phaseolus filiformis Benth. Desert bean. Nonseasonal ephemeral

vine. Flowers pink. Canyon bottom, slopes, and nearby open

desert. F 84-126.

Prosopis glandulosa Torr. var. torreyana (L. D. Benson) M. C.

Johnst. [P. juliflora (Sw.) DC. var. torreyana L. D. Benson].

Mezquite; western honey mesquite; hu’upa (Yaqui). Gradually

winter deciduous, the new leaves and flower buds emerging in

March. Flowers yellow, March-April and sporadically through

the summer. Scattered shrubs and small trees to 5+ m along the

canyon bottom; rare until the mid-1980s, the spread associated

with increased cattle grazing and disturbance. Also several small

trees and one ca. 14 m with a trunk 197 cm circumference at

Nacapule Spring. Common on the nearby open desert and at the

canyon entrance. F 92-1052, 94-847.

Rhynchosia precatoria DC. Ojo de chanate; champuusi, santa

puusim (Yaqui). Perennial vine growing over shrubs; leaves vel-

vety pubescent, the stems and leaves drought deciduous. Flowers

dull yellow with red-brown markings. Seeds shiny red and black.

Growing and flowering with summer-fall rains, the pods maturing

in October. Canyon bottom and north-facing slopes. F 54-116,

Phillips 75-164.

Senna covesii (A. Gray) H. S. Irwin & Barneby [Cassia covesti A.

Gray]. Hojasen, daisillo; kau ohasen (Yaqui). Herbaceous or

suffrutescent perennial, probably short-lived; stems and leaves

drought deciduous. Flowers yellow; warmer months. Sandy soil at

canyon entrance and scattered in nearby open desert. F 94-852.

Sphinctospermum constrictum (S. Watson) Rose. Hot-weather an-

nual. Flowers inconspicuous, white with lavender. Mostly on rocky

slopes and gravelly soil of the canyon bottom. F 85-1120, 85-1332.

Tephrosia vicioides Schlitdh. [T. tenella A. Gray]. Nonseasonal

ephemeral or annual, occasionally short-lived perennial. Petals

pink-purple, drying wine-colored, <8 mm. F 11964, 85-547.

Wiggins (1964) listed 7: tenella as a synonym of T. purpurea (L.)

Pers. However, 7. purpurea is an Old World species not present in

Mexico (see Mc Vaugh 1987).

Zapoteca formosa (Kunth) H. M. Hern. subsp. rosei (Wiggins) H.

M. Hern. [Calliandra rosei Wiggins; C. schottii S. Watson subsp.

rosei (Wiggins) Felger & Lowe]. Slender shrub 1.5—3 m; tardily

drought deciduous in moist habitats, quickly deciduous in dry

habitats. Stamens pink to pale lavender with whitish bases; sum-

mer. Mostly in shaded habitats; canyon bottom and on brushy

north- and east-facing slopes of the canyon and nearby hills. F

4083, 84-95.

The Flora of Canon de Nacapule: A Desert-Bounded Tropical Canyon near Guaymas, Sonora, Mexico 27

FOUQUIERIACEAE—Ocotillo Family

Fouquieria

1. Stems long, mostly straight and wandlike, ascending to erect,

usually not branched above; trunk very short, usually

appearing trunkless ...... ... F. splendens

1’ Stems and major limbs branched above; trunk(s) thick and

well developed.

2. Inflorescences relatively compact, usually longer than wide;

pedicels)2—61(ES) nme cccrcterceere encase F. diguetii

2' Inflorescences usually relatively loose and open and as wide

or wider than long; pedicels (3—) 5-30 mm. F. macdougalii

Fouquieria diguetii (Tiegh.) I. M. Johnst. Palo adan; mureo

(Yaqui). Shrub, often with rather thick limbs and a short trunk.

Flowers red; various seasons. Rocky north-facing slopes but most

common on south-facing slopes, nearby open mountain slopes,

and the open desert. F 92-1040.

Three of the five Sonoran Desert species freely intermingle in the

mountains from the vicinity of Nacapule to about 5 km east of Bahia

San Pedro. In this region F: diguetii locally reaches maximum popu-

lation density in more xeric habitats than does F: macdougalii (Felger

1966). In all three species the leaves are produced with sufficient

rainfall at any time of year and are quickly drought deciduous. The

flowers attract hummingbirds.

Fouquieria macdougalii Nash. Ocotillo macho; tree ocotillo;

mureo (Yaqui). Large shrub or small tree to 4+ m with a thickened,

twisted trunk and lower limbs, the bark often waxy yellow-brown

and peeling in dry seasons. Flowers bright red; various seasons.

Slopes on both sides of the canyon, apparently largest and best-

developed on north-facing slopes; also common in the surround-

ing mountains and the nearby open desert. F 11972, 92-1061.

Fouquieria splendens Engelm. subsp. splendens. Ocotillo; mureo

(Yaqui). Shrub with multiple, slender stems. Flowers red-orange;

February—March. Hot, exposed slopes, mostly near the canyon

rim and on high south-facing slopes. This species, widespread in

the deserts of southwestern North America, is here at its southern-

most limit in Sonora. F 85-542.

HYDROPHYLLACEAE—Waterleaf Family

1. Leaves sessile or gradually tapering into the petiole, oblan-

ceolate, the margins entire or inrolled; inflorescences not

coiled or the flowers solitary ............ccecececceeeeseeceseesereesees Nama

1’ At least the lower leaves petioled, the petiole and blade clearly

differentiated, the blades pinnatifid or dissected; inflorescence

COM CE ere seco Soes ce. cences cau vent vi vesttbassenes tsa na ns aaveutectengs Phacelia

Nama hispidum A. Gray var. sonorae C. L. Hitchce. Spring ephem-

eral. Corollas lavender with a yellow throat. Canyon bottom near

entrance and open desert. F 85-235. Var. sonorae occurs along the

coast from the vicinity of San Carlos and Guaymas southward,

var. hispidum in the desert to the north.

Phacelia scariosa Brandegee. Spring ephemeral with unpleasant-

smelling viscid herbage. Flowers pale lavender. Canyon bottom

and slopes. F 85-247, 95-116.

KRAMERIACEAE—Ratany Family

Krameria

1. Branches rigid and knotty with many very short spur-

branches; claws of the three upper petals fused basally, the

blades lanceolate; spines of fruit with barbs along the upper

Pantvolyshaltie eee eet etna ee icee artes aera K. erecta

I’ Branches mostly straight and without knotty spur-branches;

the three upper petals separate, the blades nearly orbicular;

spines of fruit with barbs in a terminal cluster......... K. sonorae

Krameria erecta Willd. [K. parvifolia Benth.]. Range ratany.

Spreading shrub ca. 80 cm or less in height. Flowers bright ma-

genta-purple; nonseasonal. Rocky or gravelly soil near canyon

entrance and on nearby open desert. F 85-867A.

Krameria sonorae Britton. Cosagiii; white ratany. Shrub often

1.5-2.5 m, the stems slender, spreading, and flexible. Leaves

sparse, quickly drought deciduous. Sepals and lower petals nearly

white inside, with red or red-lavender stripes and tinges, fading

pink-lavender. Spines on the fruits bright red to red-brown and

barbed only at the tip. Dry habitats, canyon mouth and nearby

open desert. Burgess 6527; F 94-867; Phillips 75-180.

Simpson (1989) treated K. sonorae as a synonym of K. grayi

Rose & Painter. However, they are distinct in the field and as her-

barium specimens and should be maintained as distinct species. The

southern limits of K. grayi in Sonora, in the vicinity of Bahia Kino

and Hermosillo, closely approach the northern limits of K. sonorae.

Their geographic ranges are apparently allopatric. I have not seen

plants with intermediate characters. K. sonorae is distinguished from

K. grayi by being conspicuously taller (often >2 m, versus usually <1]

m for the latter), usually having more open branching, longer stems,

greener, strigose leaves and young stems, conspicuously and consis-

tently lighter-colored flowers, especially the lighter-colored lower

petals, and differently shaped bracts.

LAMIACEAE (LABIATAE)—Mint Family

Hyptis emoryi Torr. [H. emoryi var. amplifolia 1. M. Johnst.; H.

emoryi var. palmeri (S. Watson) I. M. Johnst.]. Salvia; desert laven-

der; vivino (Yaqui). Shrub 1.5—2.5 m, the herbage densely white-

pubescent with dendritic hairs, the leaves olive-green to whitish

depending on moisture conditions and tardily drought deciduous.

Flowers small, lavender blue and fragrant, visited by honeybees and

hummingbirds; flowering nonseasonally, often profusely, especially

in spring. Near the canyon entrance and on the nearby desert. F 85-

582; Starr 714.

LOASACEAE—Loasa Family

1. Flowers white or green and yellow ...........:cceeceeeceees Eucnide

1’ Flowers orange Mentzelia

Eucnide

lePerennialssflowershwhitebecscssetncesetcccece ces E. cordata

1’ Annuals; flowers green and yellow ...........cceeeeee E. rupestris

Eucnide cordata Kellogg. Bushy perennial with large drought-

deciduous leaves. Flowering at least in spring. In the San Carlos—

Guaymas region usually on cliffs, often with north-facing expo-

sures, but the one record from Nacapule is from the canyon bottom

along the trail among Ficus insipida trees. Steinmann 412.

Eucnide rupestris (Baill.) H. J. Thomps. & W. R. Ernst

[Sympetaleia rupestris (Baill.) S. Watson]. Velcro plant. Nonsea-

sonal ephemeral, the roots unusually small for the size of the plant.

Pieces of the plants adhere like Velcro owing to their barbed hairs.

Stems and petioles succulent, the leaf blades relatively thin and

bright, shiny yellow-green. Most often in crevices on canyon-wall

cliffs and rocks, occasionally in gravelly or sandy soil of the

canyon bottom. F 84-606.

Mentzelia aspera L. Nonseasonal ephemeral, most often growing

with summer-fall rains. Like Eucnide rupestris, pieces of the

plants stick like Velcro. Canyon bottom, mostly in sandy or grav-

28 Richard S. Felger

elly soil in open areas, on south-facing slopes, and on the nearby

open desert. F 85-/331.

LORANTHACEAE—Mistletoe Family

1. Stems erect to spreading, straight; leaves terete, resembling

the twigs; flowers bright red... eee eee Psitticanthus

1’ Stems pendent, often in loose spirals; leaves narrowly

lanceolate, flattened, clearly distinct from the twigs; flowers

CIRERIIN COONS seracaoncessocesessec0cr20000es6640005000060004500000 Struthanthus

Psitticanthus sonorae (S. Watson) Kuijt [Phrygilanthus sonorae

(S. Watson) Standl.]. Parasitic on Bursera microphylla. Flowers

visited by hummingbirds; nonseasonal. Open desert adjacent to

the canyon and south-facing slopes. F 92-1061; Starr 715.

Struthanthus palmeri Kuijt (S. haenkei (C. Presl) Engler s. /., in

part; S. hankeanus (C. Presl) Standl.; S$. hankeanus var. angustus I.

M. Johnst.]. Toji: chichijam (Yaqui). Parasitic on Acacia willard-

iana, elsewhere in the region also on other hosts, especially

Prosopis. “Struthanthus palmeri is the most northerly of all Loran-

thaceae (excluding Viscaceae) 1n the New World” (Kuijt 1975:25).

F 95-45.

MALPIGHIACEAE—Malpighia Family

1. Stems vining, semi-vining, arching, or trailing; fruits winged.

2. Stems vining or not; leaves 2.5—11 cm; fruits with four large

papery wings, wider than long, 2—3.5 cm .............. Callaeum

2' Stems all vining; leaves <5.5 cm; fruits with two or three

samaras, each 6—13 mm, the wings longer than wide ............

SRE Serle cee oti cotta anee etn eeees srntroncctan ren cee rene Dees t waite Janusia

1’ Stems erect to spreading, not vining or as above; fruits not

winged.

3. Shrubs, usually 1.5 m or more; leaves alternate ....................

Bee Rh SAN conc d wescaen ee coos ose eecuensettouste Nias Echinopterys

3’ Subshrubs usually <1 m; leaves opposite ............. Galphimia

Callaeum macropterum (DC.) D. M. Johnson [Mascagnia

macroptera (DC.) Nied.]. Gallinita. Bushy perennial in arid habi-

tats, robust vine in better-watered habitats with denser vegetation.

Flowers yellow; various seasons. The common name relates the

unusual winged fruits to the wattles of a chicken. Canyon bottom,

mostly in the more open, xeric habitats. F 8046.

Echinopterys eglandulosa (A. Juss.) Small. Shrub to 2 m. Leaves

alternate, gradually drought deciduous. Flowers bright yellow and

very showy; various seasons with moisture and warm weather.

Near the canyon entrance and on north-facing slopes. Starr 222.

Galphimia angustifolia Benth. [Thryallis angustifolia (Benth.)

Kuntze]. Suffrutescent perennial with mostly short erect stems.

Flowers bright yellow; various seasons following rainfall. Canyon

bottom. F 84-159, 85-865.

Herbarium specimens were annotated as Galphimia brasiliensis

(L.) A. Juss. subsp. angustifolia (Benth.) by Bruce Macbryde in 1970.

However, the combination has not been published. According to Wil-

liam R. Anderson (personal communication, 1994), Macbryde “is right

that the North American plant is very close to the South American

species, which is exceedingly variable. On the other hand, the northern

one is probably sufficiently distinct that it can always be recognized,

and it is disjunct. So until some brave taxonomist is willing to wade

into this difficult genus, it is best to sick with G. angustifolia.”

Janusia

|. Leaves usually larger, broadly elliptic, widest at middle ..........

BELA ccorat ache oe eet aad teen cece Meee J. californica

I’ Leaves usually smaller, lanceolate, broadest below middle ......

SEER CORE ECE ELE OO EERE CEPR CECE REECE OSE PEC EE Eee RCE Se J. gracilis

Janusia californica Benth. Perennial vine with wiry stems; leaves

gradually drought deciduous. Flowers yellow; with warm weather

and moisture. Common and widespread in the canyon bottom, on

slopes, and on the open desert. F 85-/154; Starr 210.

Janusia gracilis A. Gray. Resembles J. californica but distin-

guished by leaf shape and size. Generally in more xeric habitats

than J. californica. South-facing canyon slopes. F 95-20.

MALVACEAE—Mallow Family

|. Fruit a capsule, the segments (carpels) persistent and not

falling away at maturity (opening through longitudinal splits

between the carpels or along the inner seam of the carpels into

the middle or “top” of the capsule) ...........:eceeeseeeeeee Hibiscus

1’ Fruit a schizocarp, the segments (mericarps) separating and

falling at maturity.

2. Subshrubby perennials, the flowering branches long and

very slender, the upper leaves sessile, cordate, or

amplexicaul at the base and clasping.

3. Fruits not globose, not readily breaking apart, the

IMELIC ANP SiO wet covcbeecseseccs eeeec cute coe tte sceeceeee ae Briquetia

3’ Fruits globose, like a tiny paper lantern, readily breaking

apartatheimentcanpsWlO SID eee ee eece cee Herissantia

2' Herbaceous to shrubby, the flowing branches not unusually

long and slender, the upper leaves petioled.

4) Mericanps) shanp=Deaked esse cece este ssestee esas eeceneeeen Sida

4' Mericarps not sharp-beaked.

5. Plants nearly glabrous or sparsely pubescent with soft

white hairs mostly <1 mm; leaf blades as broad as

long, orbicular to kidney-shaped; petals ca. 0.5 cm,

whitejto)paledavendenpeecs sees cence eee Malva

5’ Plants conspicuously pubescent; leaf blades mostly

longer than wide, not orbicular or kidney-shaped;

petals >1 cm, yellow to orange.

6. Upper and lower halves of mericarps similar, not

reticulate on sides, not winged ............:.00 Abutilon

6’ Upper and lower portion of mericarps markedly

dissimilar, the mericarps reticulate on sides, with

flared membranous wings above.

7. Involucel (floral bracts subtending flower) absent.

dug Su scwstebe.seavedecsdvaseussparce tec teestlucnawesreemene Horsfordia

7’ Involucel of three bractlets per flower. Sphaeralcea

Abutilon

1. Calyx lobes not overlapping, the fruiting calyx about 1/4 to 1/2

as long as the mericarps; petals with a maroon spot at base;

MUL ESRWAtHESNIMEn CanpSteeeseescesseeteecncce ote te serene A. incanum

1’ Calyx lobes overlapping basally, the fruiting calyx at least 3/4

as long as the mericarps; petals of a single color; fruits with 8—

10 mericarps.

2. Shrubby; herbage rough to the touch, the hairs often

yellowish, the leaves about the same color on both sides;

calyx about as long as mericarps; fruits 9-14 mm.................

Dea red a faces saved oe ce cud uaa eee cee cae eget ct eae eRe EES A. abutiloides

2’ Somewhat herbaceous perennials, dying back to ground in

drought; herbage soft to the touch, the leaves markedly

bicolored; calyx shorter than the mericarps; fruits 7-8 mm ....

wa SI eS an a dat SN Be OR eee ee a cae eee A. parishii

Abutilon abutiloides Jacq. [A. lignosum (Cav.) G. Don; A. scabrum

S. Watson, Proc. Amer. Acad. 24: 41, 1889]. Shrub often 1.5-2.5

(—3) m. Flowers orange; warm weather. Fruiting calyx about as long

as the mericarps, the mericarps 10. Understory of canyon bottom

and mostly on north-facing slopes. F 84-619, 85-1189.

This species is closely related to A. californicum Benth., a Gulf of

California segregate of the more widespread A. abutiloides (Fryxell

1988, Strong 1977). With the exception of those from Nacapule, all

The Flora of Canon de Nacapule; A Desert-Bounded Tropical Canyon near Guaymas, Sonora, Mexico 29

of the many twentieth-century collections of this species complex

from the entire Guaymas region (from near the Rio Yaqui north to

Tastiota) are A. californicum. Palmer’s late nineteenth-century type

collection of A. scabrum is reported to be from Guaymas, probably

San José de Guaymas, or “Old Guaymas,” see McVaugh (1956).

Nacapule, F 85-1789; Guaymas, 1887, Palmer 97 (type of A.

scabrum, GH, not seen, cited by Fryxell 1988).

Abutilon incanum (Link) Sweet. Tooko huya (Yaqui). Slender-

stemmed shrub. Petals pale orange with a maroon spot at base.

Flowering and fruiting nonseasonally. Mostly along the canyon

bottom and on north-facing slopes. F 85-544A; Starr 718.

Abutilon parishii S. Watson. Riptia (Yaqui). Suffrutescent peren-

nial or subshrub, open and sparsely branched with slender stems.

Leaves velvety with dense stellate hairs, darker above. Inflores-

cences of slender-stemmed sparsely branched terminal panicles

rising to 1-1.8 m and well above the foliage; flowering also from

leaf axils. Flowers yellow; warmer weather, opening between 5 and

6 PM. Mericarps about 10. Common in sandy soil and colluvium

near mouth of canyon and scattered through the canyon bottom in

open areas. At scattered localities northward to southern Arizona

(Van Devender et al. 1995). Bertelsen 92-154; F 92-1017; 94-885.

Briquetia sonorae Fryxell. Subshrub 1—1.5 m, open and sparsely

branched with unusually slender stems; growing and flowering

with hot, moist weather. Leaves widely spaced, the blades thin,

darker green and glabrate above, lighter green with stellate hairs

below, the margins toothed; vegetative leaves often 7-14 cm, their

petioles slender and often about as long as the blades, the upper

leaves (on flowering branches) smaller, sessile, and perfoliate.

Panicles and racemes long and slender. Corollas orange. Fruits ca.

1 cm wide, readily breaking into eight mericarps, each two-celled

and each cell one-seeded, the lower cell smaller and indehiscent,

the upper cell larger, broader, and dehiscent. Seeds 1.9—2.2 mm;

the seed of the lower cell mostly glabrous, the seed of the upper

cell densely and minutely hispid with often slightly hooked hairs.

Densely shaded steep north-facing slopes near the canyon bot-

tom and along the canyon bottom adjacent to the north-facing can-

yon wall. Endemic to west-central Sonora from near Hermosillo to

mountains southeast of Cd. Obregon. F 84-575, 85-1325.

Herissantia crispa (L.) Brizicky. Short-lived perennial with slen-

der stems to ca. | m. Flowers pale yellow-orange; nonseasonal,

mostly during warm, moist weather. Fruits resembling a miniature

paper lantern, the mericarps separating at maturity. Canyon bot-

tom in open, sunny habitats, slopes, and open desert. F 92-1047.

Hibiscus biseptus S. Watson. Slender subshrub 1—1.5 m. Stems

with small stellate hairs in two vertical lines decurrent from the

stipules, plus scattered larger simple and two- or three-rayed stel-

late hairs; drought deciduous. Flowers showy, bright yellow witha

purplish center; warm, moist weather. Canyon bottom and north

and south slopes. F 85-557, 85-1335.

Horsfordia newberryi (S. Watson) A. Gray. Slender few-branched

shrub, often 1.5—2 m. Petals bright yellow-orange; flowering and

fruiting at least spring and fall. Mostly on south-facing slopes; a

desert species reaching its southern limits in the Guaymas region.

F 85-562; Phillips 75-170.

*Malva parviflora L. Malva; cheeseweed. Winter—spring ephemeral.

Flowers white. Watercourse below Nacapule Spring in a heavily

grazed area. Not seen in the canyon area until 1995. F 95-55.

Sida

1. Perennial herbs with weak, often procumbent stems; herbage

and calyces with dense short stellate hairs and also larger

simple spreading hairs; leaf blades to about 1.5 cm; mericarps

S. abutifolia

1’ Slender, few-branched shrubs 1—1.4 m; herbage and calyces

with dense short stellate hairs only; leaf blades often 2—3.5

cm; mericarps usually abOUt 9... eeeesceeceseesseesereee | S. hyalina

Sida abutifolia Mill. Flowers pale yellow-orange; warmer weather.

Infrequent along the canyon bottom. Not known elsewhere in the

Guaymas-Sierra El Aguaje region, although widespread elsewhere

in Sonora and the Americas. F 85-870A.

Sida hyalina Fryxell. Flowers pale yellow-orange; warmer

months. North-facing canyon slopes. F 85-548, 85-870.

Coastal thorn scrub in southern Sonora and western Sinaloa, in-

land to the Alamos region in southern Sonora. The northernmost

records are of isolated populations at Bahia San Pedro, Las Barajitas,

and Canon de Nacapule. S. hyalina appears to be closely related to S.

xanti A. Gray of Baja California Sur and Sinaloa. S. xanti is glandu-

lar-viscid while S. hyalina is not.

Sphaeralcea—Mal de ojo; globe mallow

1. Perennials; mericarps two- or three-seeded, the dehiscent

section more than half as long as the body ............. S. ambigua

1’ Annuals; mericarps one-seeded, the dehiscent section less than

haligasilarceras; the lb od yereeesees eee een S. coulteri

Sphaeralcea ambigua A. Gray. Heoko kuta, ochoko kuta (Yaqui).

Subshrub; flowers orange. Locally rare on sandy soil of bench

above arroyo floodplain near canyon entrance. F 95-6/. This is a

desert species, otherwise known only as far south as Bahia Kino.

Sphaeralcea coulteri (S. Watson) A. Gray. Sevoa’ara, heoko kuta

(Yaqui). Annual globe mallow. Spring ephemeral. Flowers orange.

Often locally abundant in the open desert and open areas in the

canyon bottom. F 85-234.

MENISPERMACEAE—Moonseed Family

Cocculus diversifolius DC. Perennial vine, often woody at the base;

nearly evergreen. Flowers small, yellow; at least March—April. Fruits

dark purple. Canyon bottom. F 84-152; Van Devender 84-251.

MOLLUGINACEAE—Carpetweed Family

*Mollugo verticillata L. Carpetweed. Delicate hot-weather ephem-

eral. Flowers inconspicuous, green and white. Common on gravelly

soil, mostly in open areas near canyon entrance and on open desert,

less common on exposed, rocky slopes. In Sonora mostly in subtropi-

cal scrub south and east of the Sonoran Desert. F 84-599, 85-1210.

MORACEAE—Mulberry Family

Ficus—Higuera; fig.

1. Leaf blades about as wide as long, oval or orbicular to ovate

Withtalcordate baseman ree eee erne ae eee ea eee F. palmeri

1’ Most leaf blades at least twice as long as wide, mostly

lanceolate to elliptic, not cordate at base.

2. Leaves mostly 10-18 cm, broadly elliptic to ovate, often

dull green, with both or only the lower surfaces usually

rough-scabrous; sheathing stipules 4—-8.5 cm; figs solitary at

the nodes, 2.5—3 cm wide, subtended by three scales ............

sdasSvapat cause substoaltnwauracvedensravsawerdutteed: vase Souq Stee ceeusit tes F. insipida

2' Leaves mostly 5.5—12 cm, lanceolate, shiny and smooth;

sheathing stipules <2 cm; figs paired, 1 cm wide, subtended

Lo? (0) See Lets) aseacceecobnacaocosndbasocoscodosaocoenonecseduccaseseds F. pertusa

Ficus insipida Willd. subsp. insipida |F- radulina S. Watson].

Chalate; kau chuuna (Yaqui). Fig. 7. Tree 10-15 m with massive

buttressed trunks and exposed spreading gnarled roots; evergreen

or eventually deciduous in extreme drought. Figs mottled green

and yellow-green; various seasons.

30 Richard S. Felger

Figure 7. Ficus insipida, Caiion de Nacapule, January 1996. This tree shows extensive die-back and subsequent recovery. Cattle grazing has eliminated the

former understory vegetation.

Canyon bottom among the Washingtonia palms; a few at the

spring. Cattle have severely damaged young plants and the bark of

the trees, especially at the spring. F 84-117; Phillips 75-159,

Yatskievych 82-147. A tropical-subtropical species not known else-

where in the Sonoran Desert except for a few immature plants in Las

Barajitas canyon. Otherwise the nearest population is in the Sierra

Bacatete where there are extensive groves of enormous trees along

certain canyon streams. The buttressed trunks are unique among the

trees of the Sonoran Desert region.

Ficus palmeri S. Watson [F. petiolaris subsp. palmeri (S. Watson)

Felger & Lowe]. Tescalama; cliff fig. Shrub to tree 10+ m; canyon

walls, cliffs, and rock. Seedlings germinate in rock crevices. The

roots grasp the rock and cascade down over the surface, as if

melted; if the roots reach the canyon floor or moist soil the plant

develops into a tree. Root and stem bark yellowish white. Leaves

often with pink veins. Figs edible, ca. 1.5 cm in diameter, paired

(or one may fail to develop). F 84-576; Phillips 75-178.

Ficus palmeri is widespread in the Gulf of California region of

the Sonoran Desert, and F: petiolaris Kunth is characteristic of sub-

tropical and tropical regions from eastern Sonora to Oaxaca. They

meet and apparently intergrade in the Guaymas region. In the more

arid, exposed habitats surrounding the canyon the plants have the

characteristics of F. palmeri, while in more favorable habitats, such

as near the canyon bottom, they approach F: petiolaris in appearance.

Ficus pertusa L. [F. padifolia Kunth; F. sonorae S. Watson].

Nacapule; naka’apuli, nakapuri (Yaqui). Large spreading trees in

the canyon bottom among the Washingtonia groves, smaller trees

or large shrubs on cliffs and north- and east-facing canyon walls.

An enormous nacapule tree shades Nacapule Spring, a few hun-

dred meters north of the canyon entrance; it has been severely

damaged by cattle. Evergreen at permanent water, facultatively

and tardily drought deciduous in the more xeric habitats. Fruits

edible, usually ripe in late summer and also in winter. This tropi-

cal—subtropical species reaches its northern limits in the surround-

ing mountain mass. F 84-158, 84-601; Phillips 75-85.

NYCTAGINACEAE—Four O’Clock Family

1. Stems slender, weak, prostrate-trailing; flowers in clusters of

three, the cluster resembling a single flower; “fruits”

(anthocarps) with a deep cavity formed by a pair of inrolled

wings .. Allionia

1' Stems erect to spreading, sometimes decumbent but not

prostrate; flowers often clustered but each flower conspicu-

ously separate; fruits not grooved or with four or five furrows.

2. Annuals or herbaceous perennials; stems mostly <1 m;

herbage glandular-sticky; perianth pink or white to red-

purple; fruits without peglike glands ..................+. Boerhavia

2' Perennials, usually woody at base; stems usually | m or

more; herbage glabrous; perianth yellow-green; fruits with

large peglike sticky glands... Commicarpus

Allionia incarnata L. Trailing windmills. Short-lived herbaceous

perennial with trailing stems. Flowers purple; warmer months.

Arid habitats at canyon entrance and on the nearby open desert.

Boerhavia

1. Perennials; flowers dark purple-pink ................... B. gracillima

1’ Annuals; flowers whitish to pale pink.

2. Flowers in small umbellate or subumbellate clusters. B. erecta

2' Flowers on elongated raceMes ............:cceeeeeeeeeees B. spicata

Boerhavia erecta L. var. intermedia (M. E. Jones) Kearney &

Peebles [B. intermedia M. E. Jones; B. maculata Standl.; B. tri-

quetra S. Watson]. Mochis; spiderling. Summer-—fall ephemeral.

Flowers fading with mid-morning heat. Seasonally abundant; can-

yon bottom and slopes, especially in open areas, and the open

desert. Burgess 6528; Starr 219. 1am taking a broad, “lumper’s”

view in the interpretation of this species and B. spicata.

Boerhavia gracillima Heimerl|. Herbaceous perennial with hard

knotty base. Leaves firm, semi-succulent, turning reddish in win-

ter and spring. Flowering with warmer weather. North-facing

slopes, less often in the canyon bottom. F 84-149, 84-617.

The Flora of Canén de Nacapule: A Desert-Bounded Tropical Canyon near Guaymas, Sonora, Mexico 3]

Boerhavia spicata Choisy (|B. xanti S. Watson]. Spiderling. Sum-

mer—fall ephemeral. Flowers fading with mid-morning heat. Can-

yon bottom and slopes, especially in open areas, and the open

desert. Phillips 75-78.

Commicarpus scandens (L.) Standl. Perennial to 2 m, the stems

slender and brittle with long internodes, often growing through

other shrubs. Leaves semi-succulent, tardily drought deciduous.

Flowers pale yellow-green; warmer months. Canyon bottom and

mostly north- and east-facing slopes. F 84-127; Phillips 75-154.

OLEACEAE—Olive Family

Forestiera cf. angustifolia Torr. Desert olive. Much-branched

shrub 2-3 m, with rigid branches. Leaves 15-25 mm, thickish,

linear-oblong to elliptic, dark green above, lighter green below

and markedly punctate-glandular; tardily drought deciduous.

Fruits often 1 cm, fleshy, blue-black at maturity. Flowers recorded

in January, fruits in March. Fairly common along the canyon

bottom. F 84-171, 85-856.

Widely scattered in riparian canyons in the Sierra El Aguaje re-

gion. The leaves are generally larger than those of F: angustifolia

from elsewhere.

ONAGRACEAE—Evening Primrose Family

Ludwigia octovalvis (Jacq.) P-H. Raven subsp. octovalvis [Jussiaea

suffruticosa L. var. octofila (DC.) Munz]. Warm-weather annual to

herbaceous perennial, | (—2.5) m. Stems slender, amazingly tough,

the bark shredding. Petals pale yellow, falling at a touch. After the

last fruits mature, often in December, most of the above-water

portion of the plant perishes. Emergent from shallow water or in

very wet soil in the upper part of the canyon beneath Washingtonia

palms. F 84-170, 85-1498.

Wetlands in the warmer regions of the world, but not known else-

where in the Sonoran Desert except at Las Barajitas. Otherwise the

nearest population is along the lower Rio Yaqui where the plants

become 3 m tall.

PAPAVERACEAE—Poppy Family

Argemone—Cardo; prickly poppy

1. Petals white .... A. gracilenta

NwRetal Shy ello wi peerese teres erccre sre ccetecsenscestencees ese A. ochroleuca

Argemone gracilenta Greene. Prickly poppy: tatchi’ina (Yaqui).

Annual or perhaps short-lived perennial beset with sharp prickles.

Petals large and white, the stamens yellow and very numerous;

warmer months. Open areas of the gravelly to sandy wash in the

lower part of the canyon, rare but common elsewhere in the

region. Starr 488.

*Argemone ochroleuca Sweet subsp. ochroleuca. Cardo; Mexi-

can prickly poppy; tatchi’ina (Yaqui). Annual beset with sharp

prickles. Petals and stamens yellow; warmer months. Open areas

of the gravelly to sandy wash in the lower part of the canyon, rare

but common elsewhere in disturbed habitats. Ames 12 Mar 1977.

PASSIFLORACEAE—Passion Vine Family

Passiflora—Passion vine

1. Herbage densely hairy; leaves three-lobed ................... P. arida

1’ Herbage glabrous; leaves two-lobed .................2..-. P. mexicana

Passiflora arida (Mast. & Rose) Killip var. arida. Desert passion

vine; mastaoka (Yaqui). Perennial with semi-vining to vining

stems I—1.5 m often growing over shrubs. Herbage whitish woolly.

Flowers white and lavender, ca. 3 cm wide; warmer months. Fruit

globose, 2.5-3 cm in diameter, green, the pulp sweet and deli-

cious. Scattered, mostly in dryer habitats in the canyon bottom, on

south-facing slopes, and at the canyon entrance. F 84-/2/1/.

Passiflora mexicana Juss. Perennial vine overtopping trees and

shrubs; glabrous. Leaves deeply bilobed, variable in size and

width depending on shade, season, age, and soil moisture. Flowers

purple and white, ca. 2 cm wide; fruits globose, 1—-1.5 cm in

diameter, blackish when ripe; flowering and fruiting mostly with

summer rains. Common in moist habitats along the canyon bot-

tom. F 85-845; Palmer 260, [12 Oct] 1897 (the label reads

“Guaymas,” but according to McVaugh (1956) this collection is

from “Nacapuly”); Phillips 75-147.

PHYTOLACCACEAE—Pokeweed Family

1. Herbaceous or scarcely woody at base, the stems very slender.

TEL Test ee SSC Rae Re ce ence e are Sota eee eeeeer Rivina

1’ Woody shrubs, the stems not noticeably slender.

2. Leaves narrowly spatulate to oblanceolate; fruits translucent

wihiteyandifleshiyieesserecssncescteeree ee aeceree Phaulothamnus

2' Leaves broadly elliptic to obovate; fruits red and at first

semi-fleshy, drying as capsules ..........0.0.0000 Stegnosperma

Phaulothamnus spinescens A. Gray. Putilla; snake-eyes; kuh kuta,

kus kuta, va’ako (Yaqui). Woody Lycium-like shrub, spinescent

and glabrous; drought deciduous. Flowers inconspicuous. Fruits

globose, ca. 5 mm in diameter. Canyon bottom and north-facing

slopes. F 12006, 92-1014.

Rivina humilis L. Chile de coyote; pigeon berry; wo’i ko’oko’t

(Yaqui). Bushy perennial often 1-1.2 m, the leaves thin and

quickly wilting. Flowers white; mostly with summer rains. Fruits

fleshy and red. Shaded canyon bottom with Coccoloba and

Vallesia. F 92-1051; Phillips 75-151.

Stegnosperma halimifolium Benth. [S. watsonii D. J. Rogers].

Chapacolor; wokkoi aaki (Yaqui). Shrub, nearly evergreen. Flow-

ers white, fragrant, in terminal or axillary racemes; nonseasonal.

Mostly in the canyon bottom near the entrance and at the spring.

F 92-1057; Starr 203.

PLUMBAGINACEAE—Leadwort Family

Plumbago scandens L. Estrenina. Herbaceous perennial; tardily

drought deciduous. Rachis, bracts, and calyx with stipitate glands that

stick to almost anything. The calyx glands begin exuding at anthesis.

Flowers white; nonseasonal with moist conditions. Mostly in shaded

habitats along the canyon bottom and on north-facing slopes. F 85-258.

POLEMONIACEAE—Phlox Family

Gilia sonorae Rose [Ipomopsis sonorae (Rose) A. Grant]. Sonoran

gilia. Small winter-spring ephemeral. Flowers small, pale pink.

Often cryptic among ephemeral grasses. Canyon entrance and the

open desert. F 85-233, 95-104.

POLYGONACEAE—Buckwheat Family

le Winesibearing tendmil streets eset eeree see Antigonon

1' Woody shrubs, without tendrils 2.0.0.0... Coccoloba

Antigonon leptopus Hook. & Arn. San Miguelito; queen’s wreath;

masa’ asai (Yaqui). Robust perennial vine with tuberous roots, often

covering shrubs and trees; tardily drought and winter deciduous.

Panicles terminating in tendrils; floral bracts and flowers pink and

showy; nonseasonal but flowering most vigorously with summer

rains. Abundant in the canyon bottom and on rocky slopes. Widely

cultivated in Sonora and southern Arizona. F 3388, 11884.

Coccoloba goldmanii Stand|. Multiple-stemmed shrub 3-5 m.

Essentially evergreen, although the larger leaves fall during

drought. Leaf blades 5.5-17.0 cm, nearly orbicular, rather tough,

glabrous or pubescent along veins of the lower surfaces. Dioe-

cious. Flower stalks (peduncle and raceme) 7-30.5 cm, slender,

pendent, appearing terminal. Pedicels 2 mm, the perianth 4.04.5

mm wide; sepals pale green, the filaments, anthers, ovary, style,

and stigma white. Female flowers solitary; male flowers usually in

clusters of three. Fruits 5.6-6.8 x 4.8—5.7 mm, rounded and hard.

Flowering mostly June—July; fruit ripe October-December. Can-

yon bottom in winter-shaded portion and north-facing slopes be-

low cliffs; closely associated with Vallesia laciniata. F 8038, 85-

839; Phillips 75-150; Van Devender 84-257.

A few small populations also occur in other, nearby canyons and

at Las Barajitas and Cafién los Anegados near Aguaje de Robinson.

Otherwise recorded only from a few widely scattered riparian can-

yons in southeastern Sonora, southwestern Chihuahua, and northern

Sinaloa.

PORTULACACEAE—Purslane Family

1. Leaves <3 cm; flowers sessile in leaf axils; capsules circum-

RIGTISISIIIS. ccoscacsocsosnoaocesacheatoussoaseasecoedouacesbaasnqsocnpeccodaoq0000 Portulaca

1' Leaves 2.5—10+ cm; flowers in large panicles; capsules

WWEIINTENIS cocoocssoasssazedconbadocatoccaedacedoacedocoscoasesso cao ossoxonaEonaCdooon Talinum

Portulaca

1. Roots tuberous; leaves terete-conical (may appear flat when

dry); leaf axils and flower clusters densely hairy ..........:0

BER SR CREE SCEREE Sc ceG so Soa enaceacdac ona acSacouEE HERB eS ar ne cCOECHOOCED P. suffrutescens

1’ Roots not tuberous; leaves spatulate to obovate, thick but

flattened; glabrous except for a few inconspicuous hairs.

2. Capsule rim not collar-winged, the capsule opening about at

the middle, the lid conical ........... cece P. oleracea

2' Capsule rim surrounded by a collarlike wing 1-2 mm wide,

the capsule opening above the middle, the lid shallow,

saucerlike P. umbraticola

*Portulaca oleracea L. var. oleracea [P. retusa Engelm., perhaps

not P. retusa of western authors]. Verdolaga; purslane; bwaarom

(Yaqui). Hot-weather ephemeral, succulent. Flowers yellow. Can-

yon bottom in open often grazed and disturbed places and the

nearby open desert. 85-1215, 85-1309.

Portulaca suffrutescens Engelm. Hot-weather ephemeral, succu-

lent, sometimes also growing and flowering with winter—spring

rains. Flowers orange, relatively large. Canyon bottom in gravelly

soil in open areas, arid slopes usually with shallow soil, and the

open desert. F 85-1308, 85-1506.

Portulaca umbraticola Kunth subsp. lanceolata (Engelm.) J. F.

Matthews & Ketron [P. coronata Small; P. lanceolata Engelm.].

Hot-weather ephemeral, succulent. Flowers probably yellow-orange.

Canyon bottom near entrance. Bertelsen 6 Nov 1992; F 84-128.

Talinum paniculatum (Jacq.) Gaertn. Perennial from thick, fleshy,

tuberous roots. Flowering in the first season but only during the

summer rainy season. Stems and leaves succulent, the leaves

quickly drought deciduous—by late September only the dry skel-

etons of the inflorescences remain. Flowers in loose, open panicles

30-100 cm, small, pink to dark red-purple, open about three hours

in the late afternoon. Canyon slopes, less common along the

canyon bottom. F 85-847.

32 Richard S. Felger

RHAMNACEAE—Buckthorn Family

1. Vines with tendrils on inflorescences .............cccceceeeees Gouania

1' Shrubs or trees, without tendrils.

Doe VENUE AL CLIN CZYOYSIUNS cospocceccsoaceqa0es06006560c00s0c60x55050650000 Colubrina

2' Fruits fleshy.

3. Leaves <0.5 cm wide, widest well above the middle with

prominent raised pinnate veins on the lower surfaces;

IBIS) <5) 1900007 ccacescocccsossccocecarecooccseabenc54200060500000000000 Condalia

3' Leaves >0.5 cm wide, widest at or below middle, with

three prominent main veins from the base and not

prominently raised on lower surface; fruits 8-10 mm.......

BE eee EEE Osoceccecer ac oC REOS ES CoC ERE Dor paL bo Conc Be REDUCES nHGSEO Ziziphus

Colubrina

1. Leaves dull green, pubescent, the margins entire to toothed .....

BRS Pec SERED a ICESO CECE EE Eco Ee EER EOAE RORERcADocac eBconscboSDAEcaSGD C. californica

1' Leaves bright green, glabrous or sparsely puberulent when

SOUDIVEZ, {nV TETETTEATIS GAIUS) cecccocsosconeaascoscoceonesce95866c0600000 C. viridis

Colubrina californica |. M. Johnst. [C. texensis (Torr. & A. Gray)

A. Gray var. californica (1. M. Johnst.) L. D. Benson]. California

snakewood. Much-branched hardwood shrub 2—3.5+ m. Leaves

drought deciduous. Flowers small, yellow-green. Small, localized

population along canyon floor near the entrance. F 84-570, 94-

850, 92-1043. Also at Las Barajitas. These are the southernmost

records for this desert species; the nearest record is from central

Sonora, near Ures (Turner et al. 1995).

Colubrina viridis (M. E. Jones) M. C. Johnst. [C. glabra S.

Watson]. Granadita, palo colorado. Shrub with rigid hardwood

trunks and branches. Leaves quickly drought deciduous, appear-

ing with each rainy period. Flowers small, yellow-green, the floral

disk awash in nectar at anthesis; mass flowering during the sum-

mer-fall rainy season and sometimes at other seasons. Wide-

spread; canyon bottom near entrance, south-facing slopes, and the

open desert. F 85-864; Starr 199.

Condalia globosa |. M. Johnst. var. globosa. Crucerilla, bitter

condalia; hu’upa keka’ala (Yaqui). Hardwood shrub with rigid

branches and thorn-tipped twigs. Long-shoot leaves petioled and

larger; short shoots with crowded (fascicled) subsessile leaves.

Flowers small, yellow-green, the disk at anthesis awash with

sticky, glistening nectar. Occasional along the canyon bottom and

the nearby desert. F //878. Plants of var. pubescens I. M. Johnst.,

distinguished by pubescent leaves, are common in the nearby San

Carlos—Guaymas region.

Gouania rosei Wiggins. Large vine overtopping shrubs and trees.

Flowers greenish white; at least in summer. Fruits ca. 5 mm wide

with three narrow wings; in fall and perhaps at other seasons.

Canyon bottom and north-facing slopes. F 84-93, Phillips 75-156,

Starr 218.

Ziziphus obtusifolia (Hooker ex Torr. & A. Gray) A. Gray var.

canescens (A. Gray) M. C. Johnst. [Condalia lycioides (A. Gray)

Weberb. var. canescens (A. Gray) Trel.; Condaliopsis lycioides

(A. Gray) Suess. var. canescens (A. Gray) Suess.]. Abrojo;

graythorn; hutu’uki (Yaqui). Large sprawling briarlike shrub.

Nearly leafless during dry seasons, with sparse foliage in wetter

seasons. Flowers inconspicuous, attracting many insects. Fruits

edible but hardly worth the bother. Fine 77-1.

RUBIACEAE—Madder Family

(le TRIG TMEV scconooceasccncscono56oodscedenoncdasq966650000060004504500 Hintonia

1’ Twigs armed with stout Spines ........:c:cececeereeeereeereeees Randia

The Flora of Canon de Nacapule: A Desert-Bounded Tropical Canyon near Guaymas, Sonora, Mexico 33

Figure 8. Zanthoxyluwm mazatlanum. A, Portion of along-shoot branch, drawing from Felger 85-1226 by Amy Eisenberg. B, Short-shoot twigs with several

follicles, drawing from 85-/226 by Joel Floyd.

Hintonia latiflora (Sessé & Mog.) Bullock [Coutarea latiflora

Sessé & Mog.]. Copalquin, quina. Slender shrub or small tree to 4

(—6) m. Leaves produced mostly with summer rains and gradually

drought deciduous. Flowers showy, 6—9 cm, white; summer rainy

season and sometimes in spring. Mostly in winter-shaded habitats;

canyon bottom and lower north- and east-facing slopes. F 84-129,

5-850. The bark is much esteemed for its medicinal properties

and is often harvested in Sonora and elsewhere in Mexico.

Randia

1. Twigs with spines in clusters of 2—4; fruits at least 3 cm in

diameter, rather soft, leathery, and green, falling soon after

TUPOMIM O:-2iteeri coe aeckese ce taneteesreeasuaneeiecivar eecweres R. sonorensis

1’ Twigs with spines in pairs; fruits 1.5—2.5 cm in diameter, hard-

shelled, mottled green and white, semi-persistent. R. thurberi

Randia sonorensis Wiggins. Papache borracho. Shrub to ca. 4 m;

leaves drought deciduous, appearing after rains. Flowers white;

May, the fruits ripening November—December. Canyon bottom

and lower north-facing slopes; not known elsewhere in the

Guaymas-Sierra El] Aguaje region except at Las Barajitas. F 84-

121, 85-1328; Van Devender 28 Dec 1982.

Randia thurberi S. Watson. Papache. Shrub with rigid woody

branches; leaves drought deciduous. Flowers white and fragrant;

with summer rains. Fruits ripening at least in spring, the meso-

carp (pulp) black, sweet, and edible (Felger and Moser 1985).

Canyon bottom, south-facing slopes, and the open desert. F 85-

871A, 85-876.

RUTACEAE—Rte or Citrus Family

Zanthoxylum

1. Leaf rachis winged; fruits with a stipe ............0.e Z. fagara

1’ Leaf rachis not winged; fruits sessile Z. mazatlanum

Zanthoxylum fagara (L.) Sarg. [Z. sonorense Lundell]. Hard-

wood shrub 2.5—3.5 m, with rigid branches and sharp paired

spines at the nodes of long shoots; gradually drought deciduous.

Crushed leaves with a lemonlike fragrance. Flowers inconspicu-

ous; probably with summer rains. Capsules small, splitting to

reveal hard shiny black seeds; ripening October-December. Scat-

tered along canyon bottom, north-facing slopes, and nearby ar-

royos. F 84-166, 84-1227.

Zanthoxylum mazatlanum C. 1. Sandwith (Kew Bull. 1926: 433).

Figs. 8 and 9. Dioecious shrub 34 m with well-developed hardwood

trunks and branches. Long shoots mostly armed with one to some-

times several nonpaired internodal laterally flattened stout sharp

prickles to ca. 1 cm, and with relatively larger leaves; short shoots

unarmed and with smaller clustered leaves. Herbage and inflores-

cences hispidulous, the vegetative buds ferruginous. Leaves nearly

evergreen, with a citruslike fragrance when crushed but the odor

quickly dissipating, 3.8-8.0 cm (to 14 cm on vigorous long shoots),

odd-pinnate with 3-7 leaflets, the rachis not winged; leaflets sessile to

subsessile, ovate to broadly elliptic or oval or sometimes lanceolate,

the lateral leaflets 15—33 x 7.4-16.5 mm, the terminal leaflet usually

slightly larger, the margins crenulate with glands in the notches.

Inflorescences shorter than the leaves, one- to few-flowered

racemes or corymbose panicles. Flowers inconspicuous. Sepals none.

Petals mostly promptly deciduous, five or four and the fifth petal

reduced or “missing” with a gap in its place, highly variable in shape

and size on the same flower, 0.8—1.2 mm, linear to oblong, elliptic or

ovate, pale yellow to green, somewhat fleshy, sometimes bifid at

apex, ciliolate with red hairs. Staminate flowers with two or three

stamens (from their positions the androecium appears to be 5-merous,

with gaps where “missing” stamens would be expected); filaments

pale yellow (like the petals); anthers red-brown. Pistillate flowers

with mostly one but often two carpels and sometimes with a third

reduced carpel; ovary green with clear to green rounded warty glands

34 Richard S. Felger

Figure 9. Zanthoxylum mazatlanum. Pistillate inflorescence, enlarged flower, and portion of a leaf, drawing from Purpus 382 by Joel Floyd.

(some Ovaries appear asymmetric because of these warts): style,

stigma, and disk below the ovary pale yellow, the style 0.8—1.2 mm,

on most flowers bent about 45 degrees. Fruiting pedicels 1.0—2.5

mm; follicles (carpels) mostly one but often two per flower, 4.2—7.1

mm, and sometimes also with a reduced follicle or rudiment, sessile,

somewhat obovoid-rounded to obpyriform, yellowish to red-brown

or purplish, dotted with prominent pellucid glands with clear, golden

exudate, plus a large, lateral glandular wart. Seeds 4.7—5.0 mm,

ovoid, shiny black, often partially covered with a thin, red, aril-like

endocarp. Flowering in August with hot, humid weather; fruits gen-

erally ripe at the end of the summer rainy season, September—Octo-

ber (November).

This shrub has been found in three canyons in the Sierra El

Aguaje. At Nacapule the shrubs are scattered on the steep lower

north-facing canyon slopes, east-facing slopes at the southeast side

of the canyon, and mostly along the canyon bottom, especially near

the north-facing canyon wall, which is shaded during winter months.

There are probably no more than 500 plants in this population. It

grows intermixed with Celtis reticulata, Coccoloba goldmanii,

Coursetia glandulosa, Gouania rosei, Passiflora mexicana, Sapindus

saponaria, Vallesia laciniata, Verbesina felgeri, Zanthoxylum fagara.

Alberto Burquez and Angelina Martinez-Yrizar found a popula-

tion of many shrubs of this species near Aguaje Robinson in Canon

Los Anegados, about 6 airline km northwest of Nacapule (although

separated from Nacapule by high, impassible mountains). This long

canyon drains eastward from near the center of the Sierra El Aguaje

through the ranch and waterhole known as Aguaje Robinson. The

vegetation, flora, and species richness seem to be comparable to that

of Nacapule, but the canyon remains scarcely explored botanically.

In addition, I found a single shrub at Caion Las Barajitas, on the

western, seaward flank of the Sierra El Aguaje, about 15 km north-

west of Nacapule. This canyon is more than 8 km long and likewise

supports a flora and vegetation similar to those of Nacapule. It was

about 3 km inland, growing among rich riparian thorn-scrub-like

The Flora of Canon de Nacapule: A Desert-Bounded Tropical Canyon near Guaymas, Sonora, Mexico 35

vegetation. | have explored the canyon extensively and found no

other plants of this Zanthoxylum. Perhaps there is a more extensive

population in canyons or arroyos at higher elevations of the Sierra El

Aguaje, in areas which remain inaccessible and botanically unknown

despite more than 100 years of botanical exploration in the region.

Several years ago Fernando Chiang (MEXU) identified Nacapule

specimens as Z. mazatlanum. This species was previously known

only from the holotype (K) collected at Mazatlan, Sinaloa. Figure 9

is the first published illustration of it. The available information and

specimens incdicate that the Mazatlan plants differ from the Sonoran

plants by their much longer and denser ferruginous hairs on young

leaves and twigs, many-flowered pistillate inflorescences, and by

having only one-carpeled rather than both one- and two-carpeled

fruits (Fig. 9). Although there is a fairly good match between the

Sinaloa and Sonora specimens, the question of acutal relationship

remains unresolved, and the Sonoran population might be worthy of

taxonomic distinction.

In Sinaloa Zanthoxylum mazatlanum 1s a plant of coastal thorn

scrub. Natural vegetation has disappeared from the Mazatlan region,

and the vast majority of the remaining potential habitat for Z.

mazatlanum in western Sinaloa has long been converted to agricul-

ture or is poorly explored botanically. Z. mazatlanum has not been

located elsewhere in Sonora in spite of intensive botanical investiga-

tion in the state during the past several decades (e.g., Felger and

Moser 1985, Turner et al. 1995), especially in the Rio Mayo region in

the southern part of Sonora (e.g., Friedman 1996, Martin et al. 1998),

which would seem to contain the most likely habitats. Perhaps the

most likely place to search for additional populations would be the

Sierra Libre in west-central Sonora, to the northeast of the Sierra El

Aguaje (see Yetman and Burquez 1996). The interior and higher el-

evations of this large, rugged mountain have never been explored

botanically, and investigations at its periphery indicate a flora similar

to that of the Sierra El Aguaje. Note added in proof: Two additional

populations were recently discovered, one south of Alamos, Sonora,

by Tom Van Devender, and one near El Fuerte, Sinaloa, by Ignacio

Basemo Cota and David Yetman; Z. mazatlanum seems to be rare at

both localities.

Zanthoxylum mazatlanum is a member of the subgenus Zanthoxy-

lum, with about 15 species in eastern Asia and at least three species

ranging from Central America to Canada (Brizicky 1962). This sub-

genus is probably not monophyletic, and infrageneric studies are

much needed (Beurton 1994). No other members of subgenus Zan-

thoxylum are known from northwestern Mexico, although there are

two species in subgenus Fagara, Z. fagara in Baja California Sur

and Sonora and Z. arborescens Rose in Baja California Sur.

individuals on the arroyo bottom 4 Feb 1996, Buirquez & Martinez

96-3, 96-4 (MEXU). Canon las Barajitas, vicinity of 28° 03'03.6" N,

111° 11'01.7" W, north-facing rock slope in upper part of canyon,

shrub 1.7 m, 6 Jan 1996, F 96-45. Nacapule: Daniel 2004 (ASU);

F 84-167, 84-577, 85-868, 85-1226, 92-1025, 96-84; Phillips 75-148.

Sinaloa: El Zapote, Mun. de Mazatlan, “Muelilla,” 1923, Ortega

5210 (isotype, US 1208572). Mazatlan, small tree, Jan—March 1902,

Purpus 382 (UC).

SAPINDACEAE—Soapberry Family

1. Stems vining.

2. Fruits globose, inflated capsules, not winged. Cardiospermum

2' Fruits three-winged Samaras ............-:sceccereceeceeeeeeeeees Serjania

1’. Shrubs or trees.

3. Shrubs; leaves simple; fruits papery, three-winged, three-

Seededlcapsulesarcscscssseseeeet eee tee eres Dodonaea

3' Trees; leaves pinnate; fruits firm, globose, and drupe-like.

See RE Por Sey aay OEE Eee eee erg eeer ee ee eG Sapindus

Cardiospermum corindum L. Farolitos, huevo de toro, tronador:

balloon vine; too vichom, toora (Yaqui). Perennial vine; drought

deciduous. Flowers white; various seasons. Fruits resembling

small paper lanterns. Canyon bottom, slopes, and open desert.

F §5-1200; Starr 200.

Dodonaea viscosa Jacq. Tarachique; hop bush. Shrub, the herbage,

especially the young shoots, resinous-sticky; evergreen to very

tardily drought deciduous. Flowers inconspicuous, yellow-green.

Occasional in the canyon bottom and on rocky slopes. F //899.

Sapindus saponaria L. Amolillo; soapberry. Slender unarmed tree

to 8 m with a well-developed trunk; evergreen to ultimately

drought deciduous in extreme drought. Leaves pinnate, the rachis

conspicuously winged. Flowers small, cream color, often uni-

sexual; at various seasons including November—December. Can-

yon bottom. F 85-1504; Starr 200.

Along the Sonora coast S. saponaria does not range north of the

Guaymas region, but inland it extends northward along the east side

of the desert as part of the foothill thorn scrub (subtropical scrub or

riparian thorn scrub, see Burquez et al. 1999).

Benson and Darrow (1981) reduced S. drummondii Hook. & Arn.

to a variety of S. saponaria. However, they seem best treated as dis-

tinct species. S. saponaria has a more southern distribution, ranging

south to northern Argentina, and much larger leaves and leaflets. S.

drummondii, ranging from northern Sonora east to northeastern

Mexico and north to Kansas, has much smaller leaves and leaflets.

Their distributions are allopatric in Sonora, and there is no morpho-

logical intergradation. S. drummondii is essentially a temperate, frost-

hardy species. S. saponaria 1s largely tropical or subtropical and is

highly frost-sensitive in cultivation in southern Arizona.

Serjania palmeri S. Watson. Robust sprawling perennial vine,

woody toward the base with leafy stems to 5 m. Leaves divided

into many small segments; tardily drought deciduous. Flowers

white. Localized and scattered, near the streambed and lower

slopes; also on rocky slopes of Arroyo Nacapule. I have not found

this plant elsewhere in the region except at Las Barayitas, although

Edward Palmer reported it “common about Guaymas” (Watson

1889). F 85-1218, 94-875.

SAPOTACEAE—Sapodilla Family

Sideroxylon occidentale (Hems|.) T. D. Penn. [Bumelia occidentalis

Hems!l.]. Bebelama; bumelia; vapsa (Yaqui). Large hardwood shrub

or tree to 6+ m, the bark checkered. Branches rigid, the twigs often

thorn-tipped. Flowers white; probably at various seasons including

July. Scattered along the canyon floor and on north-facing slopes.

F 85-257, Phillips 75-140.

SCROPHULARIACEAE—Figwort Family

1. Leaf margins toothed.

2. Annuals; pedicel longer than the flower, the corollas yellow.

ae ss i me Mimulus

2' Perennials; pedicel shorter than the flower, the corollas dark

DIVE ei AE Se i aesaniateebeaesset Stemodia

1’ Leaf margins entire.

3. Larger leaves not in a basal rosette; corollas not spurred.

TCLS Seis Bae Sa A 22 NO se Antirrhinum

3’ Larger leaves in a basal rosette; corollas with a prominent,

SIENGE TS PUT acetic es eee Donte et esas eee en Linaria

Antirrhinum—Snapdragon

1. Herbage glandular but not viscid; leaves linear, sessile or

Taer-id N2R\0)eerenecenemace ca etccaececanon sea eecencoctocercecnetcoeo A. costatum

36 Richard S. Felger

1’ Herbage glandular-viscid; leaves ovate to broadly lanceolate,

prominentlyspetioled Teese sccccssenesceereereerceeneene= A. cyathiferum

Antirrhinum costatum Wiggins. Spring ephemeral with elon-

gated stems usually unbranched or few-branched above. Corollas

white with pink-purple guidelines. Gravelly soil in open areas in

canyon bottom and on rocky slopes. F 85-241, 95-115.

Antirrhinum cyathiferum Benth. Desert snapdragon. Nonsea-

sonal ephemeral, often branched near the base. Corollas blue-

purple. Canyon bottom, slopes, and open desert. F 85-1193, 95-54.

Linaria canadensis (L.) Dum. Cours. var. texana (Scheele) Pennell.

Toadflax. Winter—-spring ephemeral; leaves in a basal rosette. Flow-

ers blue. Sandy soil at canyon entrance and open desert. F 85-246.

Mimulus floribundus Douglas ex Lindl. Cool-season ephemeral;

herbage slimy with glandular hairs. Corollas pale yellow. Season-

ally and locally common in wet soil beneath Washingtonia palms

in the upper part of the canyon and at Nacapule Spring. F 85-603.

Stemodia durantifolia (L.) Sw. Annual to short-lived perennial to

ca. 50 cm; first leaves in a basal rosette. Corollas dark blue. Wet

soil at pools in upper part of canyon beneath Washingtonia palms.

F 84-107; Starr 48.

SIMMONDSIACEAE—Jojoba Family

Simmondsia chinensis (Link) Schneid. Jojoba. Shrub; evergreen

to very tardily drought deciduous during prolonged drought. Dio-

ecious. Male flowers yellow-green, visited by honeybees; female

flowers green; mid-winter. South-facing slopes, canyon bottom,

arroyo near canyon entrance, and open desert. F 85-549A, S5549B.

SOLANACEAE—Nightshade Family

1. Herbage densely covered with stellate hairs, the leaves and

Stemsboenenalllyispinyiesscee entrees ssseesrsatstesrescscesee=s Solanum

1’ Hairs, if present, not stellate; herbage not spiny.

2. Hardwood shrubs ... Lycium

2' Plants herbaceous or if bushy the stems not with hard wood.

3. Corollas >10 cm; fruits Spiny ......... cee eects Datura

3' Corollas <4 cm; fruits not spiny.

4. Corollas tubular; fruit a capsule (dry) ............ Nicotiana

4' Corollas as broad or broader than long or deep (not

tubular); fruit a berry (fleshy).

5. Fruiting calyx not inflated, not growing around fruit;

corollas white; fruits bright red when ripe. Capsicum

5' Fruiting calyx completely and loosely growing

around the berry like an inflated paper lantern;

corollas yellow or purple; fruits green when ripe ......

.... Physalis

Capsicum annuum L. var. aviculare (Dierb.) D’Arcy & Eschb.

Chiltepin; huya ko’oko’i (Yaqui). Subshrub 1.0—1.3 m with slender,

brittle stems. Flowering during warmer weather. Fruits red when

fully ripe and very hot to the taste. Rare, north-facing slopes and

canyon bottom near Washingtonia palms. F 84-581, 85-251.

Datura discolor Bernh. Toloache; poisonous nightshade; tebwi

(Yaqui). Nonseasonal ephemeral but responding poorly to cooler

weather. Flowers large, white, nocturnal. Infrequent along the

canyon bottom, generally in areas disturbed by cattle, and in

nearby open desert. F 85-577.

Lycium

|. Flowers slender, longer than wide, the corolla tubular, the

lobes lavender; filaments glabrous or sparsely hairy at base of

free portion “st w.. L. andersonit

|’ Flowers as wide as or wider than long, the corollas campanu-

late (tube conspicuously expanded above), white; filaments

densely hairy at base of free portion ................... L. berlandieri

Lycium andersonii A. Gray var. andersonii [L. andersonii vat.

deserticola (C.L. Hitche.) Jeps.; L. andersonii var. wrightii A.

Gray]. Salicieso; desert wolfberry; roiya, roira (Yaqui). Thorny

shrub; drought deciduous, the leaves narrow. Flowering Decem-

ber—January and at other seasons. Fruits bright orange. Canyon

bottom, slopes, and the open desert. F 84-169.

Lycium berlandieri Dunal. Bachata, salicieso. Thorny shrub;

drought deciduous, the leaves often larger and broader than those

of L. andersonii. Flowering December—January. Canyon bottom at

entrance. F 94-882.

Nicotiana obtusifolia M. Mart. & Gal. [N. palmeri A. Gray; N.

trigonophylla Dunal]. Tabaquillo de coyote, tabaco de coyote,

desert tobacco; wo’i viva (Yaqui). Herbaceous perennial with

sticky glandular-pubescent herbage and calyces. Flowers cream

white; nonseasonal. Germinating during the winter—spring season.

F 85-574, Phillips 75-83.

Physalis—Tomatillo; ground cherry

1. Herbage glandular-pubescent, clammy or “slimy”; corollas

pale yellow with five maroon spots in the center; anthers

7OLUYT| OS) 1) <coscccocdcecenseoscoaceac2c9=s5o4E0s05ecapanedsasdec9ee0c0000000 P. pubescens

1' Herbage glabrous or nearly so, “dry” and not slimy; corollas

purple or yellow but without maroon spots; anthers yellow.

2. Perennials; corollas pale yellow ...............:..0- P. crassifolia

2' Annuals; corollas purple .... P. purpurea

Physalis crassifolia Benth. var. versicolor (Rydb.) Waterf. [P.

versicolor Rydb. var. microphylla Rydb.]. Tomatillo del desierto,

desert ground cherry; kaw toma’arisi (Yaqui). Bushy herbaceous

perennial, flowering in the first season. Flowering during warmer

months. Uncommon and scattered in gravelly soil along the can-

yon bottom and near the canyon entrance. F 92-/0/8.

Physalis pubescens L. var. integrifolia (Dunal) Waterf. Tomatillo.

Annual. Stems semi-succulent with swollen nodes; herbage pale

green, the leaf blades thin and quickly wilting. Canyon bottom in

wet soil; abundant beneath the Washingtonia palms and at

Nacapule Spring. F 84-580, 85-240.

Physalis purpurea Wiggins. Annual to herbaceous perennial.

Mostly along the canyon bottom, sometimes on lower north-

facing slopes and at Nacapule Spring. F 85-245; Starr 717; Van

Devender 28 Dec 1982.

Endemic to the Guaymas region, occurring usually in less xeric

habitats than does P. crassifolia. Waterfall (1967:212) linked it to the

P. crassifolia complex. However, I agree with Wiggins (1940:74)

that it “does not seem to be closely related to any of the other species

in the Sonoran Desert.”

Solanum hindsianum Benth. Mariola, mala mujer. Sparsely

branched spiny shrub to 2.5 m. Flowers showy with lavender

corollas and large yellow anthers; nonseasonal. Common at can-

yon entrance and on open desert, occasional on slopes, and rela-

tively rare along the canyon bottom. F 92-/031.

STERCULIACEAE—Cacao Family

1. Capsules conspicuously 5-angled.

2. Stems herbaceous; flowers yellow; capsules bristly along

ame less mmany,-SCCOC mesrenetenscsssosncsnesercacesnesseemesen Hermannia

2' Stems somewhat woody; flowers rose-lavender; capsules

TMVOL! LOMAS KYA, SIECEECIEG) sacscocccacoossoosbooscassenbado0ns6000000000000 Melochia

1’ Capsules not angled.

3. Capsules 5-seeded; flowers minute and maroon........- Ayenia

3' Capsules 1-seeded; flowers small and yellow ........ Waltheria

The Flora of Canon de Nacapule; A Desert-Bounded Tropical Canyon near Guaymas, Sonora, Mexico 37

Ayenia

1. Annuals to slender perennials, not shrubby; leaves 1—3.8 cm,

linear to narrowly lanceolate ...........c.ceceseeeceesceess A. filiformis

|’ Small shrubs; leaves 4-8 cm, Ovate vo... cece A. jaliscana

Ayenia filiformis S. Watson [A pusilla of various authors, not A.

pusilla L.]. Plant to ca. | m, slender and few-branched. Leaves

gradually drought deciduous. Growing and flowering mostly dur-

ing warmer weather. Shaded places in the canyon bottom, on

canyon slopes, and on nearby open desert. F //965, 85-557.

Ayenia jaliscana S. Watson [A. glabra S. Watson]. Shrub 1—1.6 m,

leaves gradually drought deciduous. Flowering response nonsea-

sonal. Canyon bottom among Coccoloba, and above the canyon

entrance on north- and east-facing brushy slopes. F 94-848, 95-29.

Hermannia pauciflora S. Watson. Herbaceous perennial to 30 cm

from a semi-woody caudex. Flowering response nonseasonal.

Mostly on north- and south-facing slopes, also on canyon bottom

and in arroyos in the nearby open desert. F 84-99; Starr 212.

Melochia tomentosa L. |M. speciosa S. Watson; M. speciosa var.

speciosa (S. Watson) A. Goldberg]. Dove plant. Slender-stemmed

shrub to ca. 1.5 m; gradually drought deciduous. Flowers showy,

nonseasonal. Canyon bottom, mostly in open, arid habitats and

disturbed areas, also nearby open desert. F 85-576; Starr 51.

The characters of pubescence, carpel shape, and leaf texture tend

to suggest M. speciosa during the summer rainy period but approach

M. tomentosa during dry seasons.

Waltheria detonsa A. Gray. Subshrub 50-60 cm, woody at the

base, severely grazed by cattle. Flowers bright yellow; warmer

seasons. Localized on a sandy bench near the canyon entrance.

F 95-58.

THEOPHRASTACEAE—Theophrasta Family

Jacquinia macrocarpa Cav. subsp. pungens (A. Gray) Stahl [J/.

pungens A. Gray]. San Juanico; tahsi’o, tassio (Yaqui). Small tree

with a thick trunk and dense evergreen crown of firm, spine-tipped

leaves. Corollas bright orange-red, readily falling with the at-

tached stamens. Fruits 2.0—2.5 cm, ovoid, hard-shelled; mesocarp

fleshy-gelatinous, sweet and edible (Felger and Moser 1985).

Common along the canyon bottom. F 92-1020; Phillips 75-84.

TROPAEOLACEAE—Nasturtium Family

*Tropaeolum majus L. Nasturtium. Annual with orange flowers.

A small colony found in February 1995, in the canyon bottom

along road, apparently not established. Cultivated in the

Guaymas-—San Carlos region. F 95-/21.

ULMACEAE—E]Im Family

Celtis—Hackberry

1. Shrubs, the stems usually armed; fruiting pedicels shorter than

(Ho (es) Og ULES iorree soca bacaace coterie ocaarcee eatoeeca aeons ceeea aaa C. pallida

1’ Trees, the stems unarmed; fruiting pedicels as long as or

longerthanitheruitseeeee eter C. reticulata

Celtis pallida Torr. subsp. pallida [C. tala Gillies var. pallida

(Torr.) Planch.]. Garambullo; desert hackberry; kunwo, kungo

(Yaqui). Briarlike shrubs to 4 m; evergreen to tardily drought

deciduous. Flowers inconspicuous, green or yellow-green. Fruits

orange, with a thin but fleshy, semi-sweet, edible pericarp; fruits

abundantly in early fall, sparsely at other seasons. Canyon floor in

the lower part of the canyon and the nearby open desert. F 85-

1302, 92-1016.

Celtis reticulata Torr. Ciimaro, cumbro; canyon hackberry, western

hackberry; kumaro (Yaqui). Tree to 6+ m; trunk well developed, the

bark smooth and gray. Leaves evergreen, highly variable, nearly as

wide as long, with entire margins; sometimes producing new growth

and leaves even during mid-winter. Fruits hard and dull red. Com-

mon along the canyon bottom. F 3/2/, 85-1201.

Not known elsewhere in the Guaymas-—Sierra El Aguaje region.

The Nacapule trees and those from southern Sonora (e.g., the Alamos

region) have smooth trunks, without the irregular corky ridges char-

acteristic of the species in northern Sonora and Arizona. Further-

more, the trees of the northern populations are winter deciduous.

URTICACEAE—Nettle Family

Parietaria floridana Nutt. [P. hespera Hinton var. californica

Hinton]. Desert pellitory. Winter—spring ephemeral with delicate

semi-succulent stems and quickly wilting leaves. Mostly in shaded

habitats including the canyon floor, north-facing slopes, and open

desert. F 92-1033.

VERBENACEAE—-Vervain Family

1. Stems including twigs rigid, not brittle, the twigs spinose-

tipped; inflorescences racemose, the flowers pedicellate ..........

idbesteaarna ova che teucceesterereshertateretees eae death te ea a neers Citharexylum

1’ Stems including twigs brittle, not rigid, the twigs not spinose-

tipped; inflorescences spicate or capitate, the flowers sessile or

nearly so.

2. Flowers in a headlike globose cluster, the corollas yellow,

fading orange; fruits fleshy ..............cccecceesseeseeereeees Lantana

2' Flowers in elongated conelike structures, the corollas

cream-white to pale purple with a yellow center; fruits dry.

iusapesesbusgasssatsssecetevecesussgusvscnstceesueteesnctssterieceoneteey er oreees Lippia

Citharexylum flabellifolium S. Watson. Shrub; leaves produced

after rains and quickly drought deciduous. Flowers lavender and

showy; nonseasonal. Canyon entrance and adjacent open desert.

Warren 18 Aug 1975; Wiens 93-4.

Lantana camara L. [L. horrida Kunth]. Confiturilla. Openly

branched straggly shrub to 2.5 m with powerfully scented foliage.

Flowering during warmer months. Locally rare; bottom of upper

part of canyon. F 96-75.

Lippia palmeri S. Watson. Oregano, mariola. Shrub with aro-

matic herbage; leaves appearing after rains, gradually drought

deciduous. Flowering response nonseasonal. Canyon entrance and

the adjacent open desert. The leaves are widely used in Sonora as

oregano (see Felger and Moser 1985). F 85-260; Starr 21.

VIOLACEAE— Violet Family

Hybanthus fruticulosus (Benth.) 1. M. Johnst. [Calceolaria

fruticulosa var. flavescens Dowell; Hybanthus fruticulosus vat.

flavescens (Dowell) I. M. Johnston]. Herbaceous perennial to ca.

50 cm; drought deciduous. Flowers inconspicuous, white, with

rains at various seasons. Canyon floor, north-facing slopes, and

less common on south-facing slopes and in arroyos in the adjacent

open desert. F 85-871.

The variety flavescens is distinguished by its yellowish green

herbage. However, vigorously growing plants have greener herbage.

VISCACEAE—Mistletoe Family

Phoradendron diguetianum Tiegh. [P. globyliferum Trel.]. Upright

clump of green, leafy stems. Parasitic on Celtis pallida and

Jacquinia macrocarpa near the canyon entrance. Leaves dimorphic,

38 Richard S. Felger

some branches or plants with relatively narrow, elongated, and

thinner leaves, others with broader, shorter, and thicker leaves.

These differences seem to be influenced by growth rate, season, and

flowering time. Flowers small, yellow. Van Devender 54-256.

ZY GOPHYLLACEAE—Caltrop Family

1a BrereXS 303 PS UTE OTS as yscanonendocuctcodoe eoeccooedcocddoosddaqsoadacocaod Guaiacum

IPP TB KoyeN EET OVE BLODOTENKS Sopcccccscocdcessacose0%0000000000000000000000 Kallstroemia

Guaiacum coulteri A. Gray. Guayacan; huya’awo, huyawo

(Yaqui). Large shrub or small tree with extremely hard wood;

nearly evergreen. Produces spectacular masses of indigo blue

flowers in the hot, dry season of early summer. Seeds large,

enclosed in a thin bright red aril. Canyon bottom, slopes, and

nearby open desert. F 85-867; Starr 489.

Kallstroemia grandiflora Torr. Baiborin; orange caltrop. Summer

ephemeral. Flowers showy, orange. Gravelly soils at canyon en-

trance and open desert. F 84-597.

MONOCOTYLEDONS

1. Palms, with a trunk reaching 5 m or mote ................ Arecaceae

1' Not palms, herbaceous or acaulescent rosette succulents.

2. Leaves succulent and in rosettes, the margins spiny and/or

leaf spine-tipped.

3. Flowers bisexual; leaves various colors, lacking peltate

scales, the spines not strongly recurved ........... Agavaceae

3' Flowers unisexual; leaves often silvery, with peltate

scales, the spines recurved ............ cece Bromeliaceae

2' Leaves not succulent and not in rosette, the plants unarmed.

4. Flowers conspicuous, the perianth evident: calyx green,

the corollas blue or white.

5. Emergent from shallow water; leaf blades strap-shaped

to arrow-shaped; flowers white ................ Alismataceae

5' Terrestrial habitats; leaf blades linear-lanceolate to

lanceolate; flowers blue ............eeee Commelinaceae

4' Flowers inconspicuous, the perianth not evident, reduced

to bristles, microscopic scales, or absent.

6. Cattails; leaves linear, erect, thickened, and pithy;

wetland habitats ..... oA He . Typhaceae

6' Grasses, sedges, and sedgelike plants; leaves not as

above; wetland or dryland habitats.

7. Sedges and sedgelike plants; wetland habitats or

temporarily wet soils; stems solid (pithy); leaf

sheaths usually closed; each flower subtended by a

SIN GIIS [BTEVCT rcecenosccosoodconabdnoccacnebosdocdoscoSonach Cyperaceae

7' Grasses; wetland to desert habitats; stems hollow or

solid (firm, not pithy); leaf sheaths usually open;

each flower usually subtended by two bracts (the

lemmrayandhpalea)iRrcrc.cccssscesostessccscecsscesare Poaceae

AGAVACEAE—A gave Family

Agave—Maguey; century plant; kuu’u (Yaqui)

|. Leaf margins entire except for the terminal spine; inflores-

cences unbranched or the branches small and inconspicuous ...

BELO EC GRO CAE COC ESSEC IS SECOe ESCORTS A. chrysoglossa

1’ Leaf margins spiny; inflorescences branched (paniculate).

2. Leaves obovate to lanceolate, 12—20 cm wide, with ash-

ColoredicrOssibandS ire rceccesssesscseseesceswsscsoesencess A. colorata

2' Leaves linear, usually <10 cm wide, uniformly blue-green.

Saco ber Oc SEE SESE SOE CEE SEA ICO ECC RDOOE OS THSIOES NORCO A. vivipera

Agave chrysoglossa |. M. Johnst. Amole. Solitary or occasionally

offsetting (commonly forming offsets in cultivation). Leaves slen-

der, thick, green to moderately glaucous. Flowers yellow; late

March—May. North-facing rocky slopes and cliffs.

Agave colorata Gentry. Maguey; banded century plant. Solitary or

producing a few offsets. Leaves 50-100 cm, glaucous gray and often

with ashy or purple-brown to reddish bands (cross-zoned). Flowers

clear yellow; late spring—June. Fairly common on north-facing slopes,

infrequent on other slopes and at higher elevations. Boutin & Kimnach

3273 (HNT); Gentry 19881, 23560; Phillips 75-161.

Agave vivipera L. vat. vivipera |A. angustifolia Haw. var. angusti-

folia (see Forster 1992); A. owenii I. M. Johnst.; A. pacifica Trel.; A.

yaquiana Trel.]. Bacanora, lechugilla, maguey; narrow-leaf century

plant. Usually suckering and forming small colonies. Flowers yel-

low-green, at dusk producing a strong odor like overripe apricot

fruit; February. Scattered across the open desert.

ALISMATACEAE—Water Plantain Family

Echinodorus berteroi (Spreng.) Fassett [E. rostratus (Nutt.)

Engelm.]. Emergent aquatic annual. Rare, in a pool in the upper part

of the canyon. It was not seen prior to 1994 and perhaps grew from

a bird-transported seed. F 94-865. Common in standing water of

roadside ditches and other swampy habitats in the region, especially

south and east of Guaymas.

ARECACEAE (PALMAE)—Palm Family

1. Petioles unarmed (entire), the leaves prominently costapal-

mate (petiole extending well into blade on the lower surface),

the blade decurved, not flat; inflorescences shorter than or

sometimes as long as the leaves 20.0.0... cccceeeeeeeeeeeeeees Sabal

1’ Petioles armed at least on younger plants, the leaves not or

only moderately costapalmate, the leaf blades flat or nearly so;

inflorescences longer than the leaves.

2. Petioles armed on all plants; leaf blades tough and dull

green or silvery; sepals separate, entire; fruits rounded, 1.5—

Pi Crmmnydiameterperenecenceces esses wesc Brahea

2' Petioles armed on younger plants, entire or nearly so on

taller, adult palms; leaf blades shiny green; sepals united

below, the lobes with ragged margins; fruits rounded to

LUTON, S11" C11 ecoccsscosessosooscaqceo0s090002535459H000000000 Washingtonia

Brahea elegans (Franceschi ex Becc.) H. E. Moore [Erythea

elegans Franceschi ex Becc.; Erythea clara L. H. Bailey, Gentes

Herb. 6:197, fig. 69, 1943; Brahea clara (L. H. Bailey) Espejo &

L6pez-Ferrari; B. roezlii sensu Wiggins 1964, not B. roezlit Lin-

den]. Palmilla. Trunks to 10 (-15+) m. Leaf blades moderately

costapalmate, relatively flat, tough, dull green to gray or bluish

(glaucous), densely to moderately silvery-lepidote. Flowers white;

early summer prior to the rains. Fruits ripen in April.

Canyon bottom including the drier, lower portions, in the upper

canyon intermixed with the other two palms. Also common on rocky

slopes including cliffs to peak elevations in the surrounding moun-

tains, often growing from rock crevices. The hesper palms of the

Sierra El Aguaje, Sierra Libre, and to the northeast in Sonora appear

to be conspecific (Felger and Joyal 1999). Bailey 4 (BH), 263 (BH);

F 3382, 11985.

Sabal uresana Trel. Palma del taco; Sonoran palmetto; tako

(Yaqui). Trunks to 10+ m; leaves reaching 3-4 m, the blades

relatively tough, glaucous but otherwise glabrous, and conspicu-

ously decurved (not flat). Inflorescences shorter than the leaves.

Flowers white; April-June, mostly May. Fruits depressed-glo-

bose, 18-20 mm wide, ripening in August.

Canyon floor near the streambed, densest along permanent water

and extending into areas of temporary water. The fruit, called taco, is

eaten in Sonora. Bailey 26 (BH).

The Flora of Canon de Nacapule: A Desert-Bounded Tropical Canyon near Guaymas, Sonora, Mexico 39

Washingtonia robusta H. Wendl. Abanico; Mexican fan palm.

This is the tallest palm native to Sonora (Felger and Joyal 1999)

and the tallest tree in the canyon, where it reaches ca. 20 (—25) m.

Petioles of younger trees with stout spines, those of the taller ees

essentially entire. Leat blades nearly flat except the distal portions

of the segments are free and often pendent. Flowers white; May—

June. Fruits ellipsoid to rounded, 7.5—9.0 mm, blackish, often

ripening in fall, the pericarp sweet like a date.

Restricted to the streambed in the upper canyon where it locally

outnumbers the other palms. Also at several other oases in the Sierra

El Aguaje; otherwise native only to Baja California Sur. This palm is

now one of the most widely cultivated palms in the world, especially

in Mediterranean and subtropical regions. It is planted extensively at

San Carlos and Guaymas. Bailey 3 (BH), 262 (BH); F 3118, 92-1027.

BROMELIACEAE—Pineapple Family

Hechtia montana Brandegee. Mescalito. Rosette-forming peren-

nial, usually suckering profusely. Leaves silvery-green, sometimes

reddish, semi-succulent, the margins with sharp recurved spines.

Dioecious. Staminate and pistillate inflorescences distinctive, to |

m. Flowers inconspicuous; August. Common on protected rocky

slopes and cliffs with north and east exposures and at higher eleva-

tions, often with Euphorbia ceroderma; less common on south- and

west-facing slopes. Turner 79-307; Yatskievych 82-152.

COMMELINACEAE-—Spiderwort Family

Commelina erecta L. Hierba del pollo; day flower. Herbaceous

perennial, appearing with summer rains and sometimes growing

with winter—spring rains. Flowers blue, opening at dawn and deli-

quescent by mid-morning on summer days. Canyon bottom and

north-facing slopes. F 84-98

CYPERACEAE—Sedge Family

1. Leaves reduced to basal sheaths, the blades lacking; inflores-

cence a single terminal spikelet ........0.0.0.0cceeeeee Eleocharis

1' Leaf blades present but sometimes relatively short and near

base of stem; inflorescence of more than one spikelet.

2. Scales of spikelets two-ranked (distichous), not spiralled.....

SrabeScaoatoor ca co CO SORES CcCacEtcocrooENSeea ta beara ida cad Cyperus

2' Scales of spikelets spiralled.

3. Annuals; stems and leaves similar, filiform to narrowly

linearsperianthvabsen tienes tecese cesses Fimbristylis

3’ Perennials; stems and leaves quite different, the leaf

blades flat, broadly linear; perianth of three paddle-like

SUC CUNCS ene ete aan re mee Neo cgncrener sees ec gone oes Fuirena

Cyperus

1. Perennials, >15 cm; scales of spikelets straight, the tips

awnless and not recurved C. odoratus

1’ Annuals, mostly <10 cm; scales subtending flowers with

RECUIVE MAW UIPSycersseereceste ese tee eects recs C. squarrosus

*Cyperus odoratus L. [C. ferox Rich.]. Stems triangular. Spikes

slender, the styles three-branched. Flowering at various seasons.

Locally common in pools of upper canyon beneath Washingtonia

palms. F 84-246; Phillips 75-163; Van Devender 28 Dec 1982.

Cyperus squarrosus L. [C. aristatus Rottb.]. Dwarf sedge. Di-

minutive tufted sedge; winter—spring. Wet soil at edge of pools in

the upper canyon. I noted it during spring 1984 but have not seen it

in the canyon since then.

Eleocharis geniculata (L.) Roem. & Schult. [Scirpus geniculatus L.;

Eleocharis caribaea (Rottb.) S.F. Blake]. Tulillo; spikerush. Small

grassy annual. Edges of pools in the upper canyon. F 3384, 84-125.

Fimbristylis annua (All.) Roem. & Schult. Warm-weather ephem-

eral. Achenes white with an iridescent sheen like ancient glass.

Emergent from pools in the upper canyon beneath Ficus insipida

and Washingtonia. Locally common in October 1984 but appar-

ently extirpated, presumably because of cattle grazing. F 84-55.

Fuirena simplex Vahl. Umbrella-grass. Herbaceous perennial;

stems rounded in cross-section. Emergent from pools in the upper

canyon beneath the Washingtonia palms; locally common. F 3385,

84-615; Daniel 1976 (ASU).

POACEAE (GRAMINEAE)—Grass Family

1. Low, spreading perennials with stolons and/or rhizomes, often

forming dense colonies or mats.

2. Plants with long, slender, nonscaly stolons; spikes alternate

on the axis; spikelets in threes and awned ........ Cathestecum

2' Plants with creeping, scaly rhizomes; spikes digitately

arranged at the summit of the stem; spikelets single,

AWMIESS oes ssvcodoies cote torszteceibeten ears Ste oseuseubetececs oot Cynodon

1’ Annuals or perennials without conspicuous stolons or rhizomes.

3. Stems somewhat bamboolike, mostly >1 m; leaf blades

mostly >2 cm wide; glumes and Jemma with a small

terminal tuft of hairs «0.0.0... Pee LOSIAGLS

3’ Stems not bamboolike, mostly <1 m; leaf blades mostly 1

cm wide or less; glumes and lemmas without a terminal tuft

of hairs.

4. Spines or bristles surrounding or just below the spikelets;

sometimes spines or bristles united into a bur enclosing

the spikelets.

5. Spikelets not enclosed in burs, but most spikelets

subtended by slender bristles and breaking off above

therbristles; 22.4 Ata ee eee Ee Be ee enn Setaria

5’ Spikelets enclosed in burs, the bur falling as a unit with

the attached bristles or spines.

6. Burs with sharp, stiff spines, the spines and bristles

conspicuously united at least in lower fourth of the

10] Ni eeertereterencre rece ee aeercrare cece eee ee Cenchrus

6' Burs with flexible bristles, the bristles separate

except scarcely united at very base ......... Pennisetum

4' Inflorescences without spines or bristles just below the

spikelets; spikelets not in burs.

7. At least some spikelets awned.

8. Inflorescences of one-sided spikes, the rachis

flattened on one side.

9. Spikes arranged laterally along the main axis;

rachis (in ours) not extending beyond spikelets .....

Jiteriteaeanbeadeittseece sta ot Ls uewba ener eres Bouteloua

9' Spikes digitately arranged at top of main axis; rachis

tip extending beyond spikelets........ Dactyloctenium

8’ Spikelets not on one-sided spikes, the rachis not

flattened.

10. Plants glabrous or scabrous, the lemma with one

or three awns each 12—20 mm ..............00. Aristida

10’ Plants pubescent with soft, often pinkish hairs on

the spikelets, the lemma with a single terminal

ENN (KO) 2 S000 ec ccccocooocoeosdecaconconcoccceccs Rhynchelytrum

7' Spikelets not awned.

11. Spikelets with two or more distinct bisexual florets.

12. Primary panicle branched two or more times, the

secondary branches usually ascending to spread-

ing; pedicels as long as or longer than the

spikelets; lower glume blunt or acute, shorter than

theplowestehl onctees see cee ence Eragrostis

12’ Primary panicle branches unbranched, spikelike,

40 Richard S. Felger

or with secondary branchlets closely appressed;

pedicels shorter than the spikelets; lower glume

acuminate, longer than the lowest floret ................

BAUER oN DN oe relate creeeeeaaee eases ets Leptochloa

11' Spikelets with one bisexual floret, sometimes also

with one or two reduced or vestigial floret(s) (the

spikelet may appear one-flowered on casual

inspection).

13. Inflorescences of digitate spikelike branches, the

spikelets sessile and evenly spaced in regular

TRONS): Gasetcoct cae Stconanctocanseossecaasosseoseadocnaabae ceeded Digitaria

13’ Inflorescences paniculate, the spikelets pedicel-

late and not in regular rows.

14. Plants hairy, including panicle branches,

branchlets, and spikelets; prominent veins of

spikelets longitudinal and transverse on upper

part of spikelet to form a netlike pattern ............

.... Brachiaria

14’ Plants variously hairy but panicle branches,

branchlets, and spikelets glabrous; prominent

veins of spikelets longitudinal only ..... Panicum

Aristida

1. Annuals; spikelets with three well-developed and flattened

ALWIL S ea es ears wel Lee Bh dees Mie ee sneer A. adscensionis

1' Perennials; spikelets one-awned, or lateral awns greatly

reduced, the awn(S) terete ........... cesses eeeeeeeeseeeeeee A. ternipes

Aristida adscensionis L. Zacate tres barbas, zacate de semilla;

six-weeks threeawn. Nonseasonal ephemeral. Widespread, mostly

in open, xeric habitats; canyon bottom, slopes, and open desert. F

92-1045; Van Devender 28 Dec 1982.

Aristida ternipes Cay. var. ternipes. Zacate arana; spidergrass.

Tufted perennial, flowering in the first season; often to nearly | m,

the panicles open with spreading branches; flowering nonsea-

sonal. Abundant and widespread but largely absent from the more

densely vegetated habitats; canyon bottom, slopes, and open

desert. F 84-103; Reina 95-102; Van Devender 28 Dec 1982.

Bouteloua

1. Perennials; basal (lower) leaves densely clumped, nodes

between them not readily visible ..............cceeeeeeeeeeee B. repens

1’ Ephemerals; basal leaves sparse, nodes between them readily

visible; common and widespread.

2. Spikes dart-shaped, with 1—4 spikelets closely appressed to

(HNVS) Gov 20 01S sessaect0cb0e00600005005005005 OSA ROB HOSEOSEEE B. aristidoides

2' Spikes comb-shaped, with ca. 20-50 crowded spikelets, the

spikelets perpendicular to the spike axis .......... .... B. parryi

Bouteloua aristidoides (Kunth) Griseb. Aceitilla, six-weeks

needle grama. Summer-fall ephemeral. Abundant, mostly in open,

arid habitats; canyon bottom, slopes, and open desert. F 85-1318;

Van Devender 8 Dec 1982.

As soon as the grain ripens and the plants dry, Pogonomyrmex

ants stream out along their pathways and carry home the whole dis-

articulated spikelets. They remove the grain at their nests and pile the

chaff in craterlike mounds around the entrances to their subterranean

colonies.

Bouteloua parryi (E. Fourn.) Griffiths. Hot-weather ephemeral,

sometimes with weak regrowth in winter or spring. Spikes includ-

ing the glumes and awns often dark purple-brown, the anthers

orange. Open desert near the canyon mouth. Starr 220.

Bouteloua parryi resembles B. barbata, which is widespread and

common in nearby, surrounding regions, except in being conspicu-

ously papillose-pilose with relatively long hairs on spikes and espe-

cially on the peduncle, rachis, and keel of second glumes. Leaf ligules

and margins of the blades also usually pilose to hispid with stout

often papillose-based hairs.

Bouteloua repens (Kunth) Scribn. & Merr. [B. filiformis (E.

Fourn.) Griffiths; B. bromoides Lag.]. Zacate navajita; slender

grama. Tufted perennial, sometimes flowering in the first season

but the spikelets not maturing; flowering mostly during warmer

months. Slopes, soil pockets in rocks, and open areas along the

canyon floor. Burgess 6377; F 85-1306; Toolin 1938.

Brachiaria arizonica (Scribn. & Merr.) S. T. Blake [Panicum

arizonicum Scribn. & Merr.]. Hot-weather ephemeral. Canyon

bottom, slopes, and nearby open desert. F 84-139, 85-1313.

Cathestecum brevifolium Swallen. Grama china. Nonseasonal,

but flowering most vigorously with moist weather during the

warmer months. Abundant; hillsides including hot south-facing

slopes and open desert. Burgess 6529; F 85-1311.

*Cenchrus brownii Roem. & Schult. Zacate toboso; sandbur.

Warm-weather annual or perhaps sometimes perennial. Inflores-

cence dense; burs with smaller as well as larger spines and a basal

collar or ring of slender spines. Several dozen plants near the

streambed beneath the palms in the upper part of the canyon.

Probably not native in the canyon. F 85-1497; Van Devender 28

Dec 1982.

*Cynodon dactylon (L.) Pers. var. dactylon. Zacate Bermuda;

Bermuda grass; mo’oko vaso (Yaqui). Flowering any season but

mostly in the warmer months. Well established and common on

moist, alkaline soils in the canyon bottom. F 84-1/2.

*Dactyloctenium aegyptium (L.) P. Beauv. Zacate de cuervo;

crowfoot grass. Warm-weather ephemeral, sometimes persisting

through the winter. Canyon bottom in wet soil and also at the

spring, especially in disturbed, grazed habitats. F 84-156, 85-

1499.

“Digitaria ciliaris (Retz.) Koel. [D. adscendens (Kunth) Henrard;

D. sanguinalis (L.) Scop. var. ciliaris (Retz.) Parl.]. Zacate

cangrejo; crabgrass. Warm-weather ephemeral, occasional in win-

ter or spring, the plants spreading, rather open, and sparse. Canyon

bottom near water, especially common in gravelly soil where cattle

grazing has altered the riparian vegetation. F 84-591], 85-1207.

Eragrostis pectinacea (Michx.) Nees. Summer ephemeral. Stems

and inflorescences delicate and filmy, the slender pedicels closely

appressed (var. pectinacea) to sometimes spreading [var.

miserrima (E. Fourn.) J. Reeder]. Widespread, especially along

the canyon bottom. F 84-592.

Lasiacis ruscifolia (Kunth) Hitche. Yo vakau, wo’i vaaka (Yaqui).

Perennial, 1.2-1.6 m; nonseasonal but mostly during warmer

months. Fruits blackish. Steep north-facing rocky slopes below

cliffs and shaded densely vegetated north-facing portions of the

canyon bottom. F 84-572, 85-1325.

Leptochloa panicea (Retz.) Ohwi subsp. mucronata (Michx.)

Nowack [L. mucronata (Michx.) Kunth; L. filiformis (Lam.) P.

Beauv.]. Zacate salado, desparramo rojo; red sprangletop. Sum-

mer ephemeral. Widespread; canyon bottom, slopes, and the open

desert and arroyos. F 84-/62.

Panicum hirticaule J. Pres| var. hirticaule. Summer ephemeral,

highly variable in size, the roots weakly developed. Widespread

and common; canyon bottom often in open areas, slopes, and open

desert. F 84-174, 85-1213.

*Pennisetum ciliare (L.) Link [Cenchrus ciliaris L.]. Zacate

buffel; buffelgrass. Tufted perennials, flowering in the first season.

The Flora of Canon de Nacapule: A Desert-Bounded Tropical Canyon near Guaymas, Sonora, Mexico

Well established along the road at the canyon entrance. This now

widespread grass, well established in the Guaymas region at least

since the 1980s, was first found in the canyon in December 1992.

F 92-1056.

*“Rhynchelytrum repens (Willd.) C. E. Hubb. [R. roseum (Nees)

Stapf & Hubb.; Tricholaena rosea Nees]. Espiga, zacate rosado,

Natal grass. Winter-spring annual. North-facing side of canyon

bottom near Ficus insipida, rare. First found in the canyon in

1994. Itis common elsewhere in the San Carlos-Guaymas region.

F 94-846.

Setaria

Coarse tuftedipenenuialsiescetesteceseestececocestesteseeere S. leucopila

1’ Hot-weather annuals .............. S. liebmannii

Setaria leucopila (Scribn. & Merr.) K. Schum. Zacate temprano;

white-haired bristlegrass. Mostly growing and fruiting in warm,

generally moist mes of the year. Canyon bottom and slopes. F

84-589, 85-1495.

Setaria liebmannii E. Fourn. Cola de zorra; summer bristlegrass.

Widespread; canyon bottom, slopes, open desert, and arroyos. F

84-165, 84-1219.

TYPHACEAE—Cattail Family

Typha domingensis Pers. Tule; cattail. Perennial, emergent from

shallow permanent water beneath Ficus insipida. Several young

plants found in the mid-1980s failed to establish themselves. This

species is common in wetland habitats at San Carlos and elsewhere

in the region.

ACKNOWLEDGMENTS

Many friends have helped with the field work; in this regard I especially

thank Mark Dimmitt, Gil Gillenwater, Silke Schneider, Jean Russell, the late

Alexander Russell, and Michael Wilson. I thank Michael Wilson, Alberto

Burquez, Fernando Chiang-Cabrera, Linda Leigh, Angelina Martinez, Mark

Fishbein, Victor Steinmann, Allan Zimmerman, and especially Charlotte

Reeder, John Reeder, and Tom Van Devender for their valuable suggestions

and information. The Wallace Research Foundation provided financial sup-

port. Several herbaria supplied valuable loans of specimens, e.g., CAS, DES,

MEXU, MO, RSA, TEX, UC, and US. Phil Jenkins, Kristen Johnson, and

Lucinda McDade of the University of Arizona herbarium greatly facilitated

the work. The geology was interpreted by Chris Eastoe.

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