THE FLORA OF CANON DE NACAPULE: A DESERT-BOUNDED TROPICAL CANYON NEAR GUAYMAS, SONORA, MEXICO Richard S. Felger INO, BS) 30 June 1999 Proceedings of the San Diego Society of Natural History ISSN. 1059-8707 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 tN 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 20 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 eS c o cS n 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 tn 120 100 on @ 3 80 a ” xe} 8 60 E re) cS 40 20 Geophytes Epiphytes wn o S f= a ° i) o = = 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 7 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 y 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 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: 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, 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 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, i) an 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) 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. LITERATURE CITED Bailey, L. H. 1937. Erythea, the hesper palms. Gentes Herb. 4:85-118. Benson, L., and Darrow, R. A. 1981. Trees and Shrubs of the Southwest- ern Deserts, 3rd ed. University of Arizona Press, Tucson. Beurton, C. 1994. Gynoecium and perianth in Zanthoxylum s. 1. (Rutaceae). Plant Systematics and Evolution 161:97—134. Boutin, F.C. 1971. Anew locality for Psilotwm nudum in Sonora, Mexico. American Fern Journal 61:141—142. Brizicky, G. K. 1962. The genera of Rutaceae in the southeastern United States. Journal of the Arnold Arboretum 43: 1-22. Burquez, A., and Martinez-Yrizar, A. 1997. Conservation and landscape transformation in Sonora, Mexico. Journal of the Southwest 39: 371— 398. Burquez, A., Martinez-Yrizar, A., Felger, R. S., and Yetman, D. 1999. Veg- etation and habitat diversity at the southern edge of the Sonoran Desert. Pp. 36-67 in R. H. Robichaux (ed.). Ecology of Sonoran Desert Plants and Plant Communities. University of Arizona Press, Tucson. Burquez, A., and Quintana, M. 1994. Islands of diversity: ironwood ecology and the richness of perennials in a Sonoran Desert biological reserve. Pp. 9-27 in G. P. Nabhan and J. L. Carr (eds.). Ironwood: An ecological and cultural keystone of the Sonoran Desert. Conservation International Occasional Paper 1. Conservation International, Washington, D.C. Daniel, T. 1984. The Acanthaceae of the southwestern United States. Desert Plants 5:162—179. Felger, R. S. 1966. Ecology of the islands and gulf coast of Sonora, Mexico. Ph.D. dissertation, University of Arizona, Tucson. Felger, R. S., and Johnson, M. B. 1995. Trees of the northern Sierra Madre Occidental and sky islands of southwestern North America. Pp. 71— 83 in L. F. DeBano et al. (eds.). Biodiversity and management of the Madrean Archipelago: The sky islands of the southwestern United States and northern Mexico. Rocky Mountain Forest and Range Experiment Station, U.S.D.A. Forest Service. Ft. Collins, Colorado. Felger, R. S., and Joyal, E. 1999. The palms (Arecaceae) of Sonora, Mexico. Aliso 18:1-18. Felger, R. S., and Lowe, C. H. 1967. Clinal variation in the surface—vol- ume relationships of the columnar cactus Lophocereus schottii in northwestern Mexico. Ecology 48:530-536. Felger, R. S., and Lowe, C. H. 1976. The island and coastal vegetation and flora of the northern part of the Gulf of California, Mexico. Natural History Museum of Los Angeles County Contributions in Science 285. Felger, R. S., and Moser, M. B. 1985. People of the Desert and Sea: Eth- nobotany of the Seri Indians. University of Arizona Press, Tucson. Forster, P. I. 1992. New varietal combinations in Agave vivipera (Agavaceae). Brittonia 44:74-75. Friedman, S. L. 1996. Vegetation and flora of the coastal plains of the Rio Mayo region, southern Sonora, México. Master’s thesis, Arizona State University, Tempe. Fryxell, P. A. 1988. Malvaceae of Mexico. Systematic Botany Mono- graphs 25. Gentry, H. S. 1942. Rio Mayo plants. Carnegie Institute of Washington Publications 527. Gentry, H. S. 1949. Land plants collected by the Velero ///, Allan Hancock Pacific Expeditions 1937-1951. Allan Hancock Pacific Expeditions 13. University of Southern California Press, Los Angeles. Godfrey, R. K. 1952. Pluchea section Stylimnus, in North America. Jour- nal of the Elisha Mitchell Scientific Society 68:238—271. Henrickson, J. 1996. Studies in Macrosiphonia (Apocynaceae): Generic recogmition of Telosiphonia. Aliso 14:179-195. Johnston, I. M. 1924. Expedition of the California Academy of Sciences to the Gulf of California in 1921: The botany (vascular plants). Proceed- ings of the California Academy of Sciences, Series IV, 12:951—1218. Kuijt, J. 1975. The identity of Struthanthus haenkei (Spirostylis haenkei) (Loranthaceae). Canadian Journal of Botany 53:249-255. Levin, G. 1994. Systematics of the Acalypha californica complex (Euphorbiaceae). Madrono 41:254—265. Lindsay, G. 1963. The genus Lophocereus. Cactus and Succulent Journal (U.S.) 35:176-192. Martin, P. S., Yetman, D., Fishbein, M., Jenkins, P., Van Devender, T. R., and Wilson, R. K. (eds.). 1998. Gentry’s Rio Mayo Plants. Univer- sity of Arizona Press. Tucson. McVaugh, R. 1956. Edward Palmer, Plant Explorer of the American West. University of Oklahoma Press, Norman. MceVaugh, R. 1987. Leguminosae. Flora Novo-Galiciana 5. University of Michigan Press, Ann Arbor. Parfitt, B. D. 1987. Echinocereus nicholii (L. D. Benson) Parfitt, stat. nov. (Cactaceae). Phytologia 63:157-158. Pinkava, D. J., Baker, M. A., Parfitt, B. D., Mohlenbrock, M. W., and Worthington, R. T. 1985. Chromosome numbers in some cacti of western North America. V. Systematic Botany 10:471-483. Rollins, R. 1941. The cruciferous genus Dryopetalon. Contributions of the Dudley Herbarium 3:199—207. Shreve, F. 1951. Vegetation of the Sonoran Desert. Carnegie Institute of Washington Publication 591. Simpson, B. B. 1989. Krameriaceae. Fl. Neotrop. Monog. 49:1-108. Steinmann, V. W., and Felger, R. S. 1997. The Euphorbiaceae of Sonora, Mexico. Aliso 16:1-71. Strong, S. K. 1977. A study of Abutilon (Malvaceae) in the southwestern United States and Mexico. Ph.D. dissertation, University of Texas, Austin. Toolin, L. J., Van Devender, T. R., and Kaiser, J. M. 1979. The flora of Sycamore Canyon, Pajarito Mountains, Santa Cruz County, Arizona. Journal of the Arizona—Nevada Academy of Sciences 14:66—74. 4 42 Richard S. Felger Turner, B. L. 1985. Verbesina (Sect. Pterophyton) felgeri (Asteraceae), a new species from Sonora, Mexico. Phytologia 57:127-129. Turner, R. M., Bowers, J. E., and Burgess, T. L. 1995. Sonoran Desert Plants: An Ecological Atlas. University of Arizona Press, Tucson. Van Devender, T. R., Steinmann, V. W., Wiens, J. F., and Bertelsen, C. D. 1995. Noteworthy Collections: Sonora. Madrojio 42:410-411. Waterfall, U. T. 1967. Physalis in Mexico, Central America, and the West Indies. Rhodora 69:82—120, 202-239, 319-329. Wiggins, I. L. 1940. New and poorly known species of plants from the Sonoran Desert. Contributions of the Dudley Herbarium 3:65-88. Wiggins, I. L. 1964. Flora of the Sonoran Desert. Pp. 189-1740 in F. Shreve and I. L. Wiggins. Flora and Vegetation of the Sonoran Desert, 2 vols. Stanford University Press, Stanford, California. Williams, J. K. 1996. The Mexican genera of the Apocynaceae (sensu A. DC.), with key and additional taxonomic notes. Sida 17:197—213. Wilson, R. T. 1978. Reconnaissance geology and petrology of the San Carlos area, Sonora, Mexico. Master’s thesis, Arizona State Univer- sity, Tempe. Woodson, R. E., Jr. 1937. New or otherwise noteworthy Apocynaceae of Tropical America, V. Annals of the Missouri Botanic Garden 24: 1 1— 16. Yetman, D. A., and Burquez, A. 1996. A tale of two species: Speculation on the introduction of Pachycereus pringlei in the Sierra Libre, Sonora, Mexico, by Homo sapiens. Desert Plants 12:23-32. 1 pen! > : Ata) 7 J oa bel if i aly, IWS, nga ipa 7