Asclepiadoideae of the Río Mayo

Introduction

This annotated checklist is based on a treatment I prepared for Gentry's Río Mayo Plants: The Tropical Deciduous Forest and Environs of Northwest Mexico, published in September, 1998 by The University of Arizona Press. This page will include corrections and updates to the published treatment of Asclepiadaceae (now Apocynaceae subfamily Asclepiadoideae) of the Río Mayo; for example, an additional species of Matelea was included before the book was published. The book is a revision of Howard Scott Gentry's classic 1942 study of the flora and vegetation of the northern Sierra Madre Occidental and includes approximately twice as many species as reported in Gentry's original study.

The area covered by this regional treatment of Asclepiadoideae includes the entirety of the watershed of the Río Mayo, as well as contiguous portions of the watersheds of the Río Yaqui and the Río Fuerte. These great rivers drain the Pacific slope of the Sierra Madre Occidental in northwestern México in the states of Sonora and Chihuahua. The region is notable for rugged topography and biotic diversity, including desert, thorn scrub, oak woods, pine-oak forest, and the northernmost tracts of tropical deciduous forest in North America. The Río Mayo originates high in the Sierra Madre, where it plunges over a rim of volcanic tuff at Cascada de Basaseáchic, reputedly the tallest waterfall in México with a 246 m free fall to the base.

Format of the checklist

In the following list genera are listed alphabetically as are species within genera. For each species or infraspecific taxon the following data are reported:

Scientific name [and selected synonymy]
Links to images
Vernacular name, with language other than Spanish indicated in parentheses.
A short description of the habit and notable characteristics of the taxon, followed by flowering phenology, followed by global distribution. Quoted material is reproduced from Gentry (1942).
Recorded or observed habitats within the Río Mayo region, followed by documented elevation range
Exsiccatae from within the Río Mayo region, listed by state

Genera of Asclepiadoideae in the Río Mayo Region

Annotated checklist of species

Asclepias angustifolia Schweigg. Photo Photo
Inmortal
Perennial herb to 75 cm with multiple stems from base, flowers white, Apr-Aug. Arizona, U.S. to Chiapas, México.
HABITAT: Canyon bottoms, hillslopes; oak woods, pine-oak forest. 1200-2100 m.
SPECIMENS SEEN: SONORA: Sierra Obscura (Gentry 504 [US]); Río Maicoba (Van Devender 95-467 [ARIZ]); Sierra Saguaribo (Martin s.n. [ARIZ]; Pennell 19,596 [US]); Rancho Santa Bárbara (Smith s.n [ARIZ]); Mesa El Campanero (Goldberg 76-158 [ARIZ, MEXU]); W of El Kípor (Steinmann 896 [ARIZ]); Yécora (Reina 95-455 [ARIZ]); Trigo Moreno (Fishbein 3678 [HCIB, MEXU, WS]). CHIHUAHUA: Sierra Charuco (Gentry 1517 [ARIZ, F, GH, MEXU, MO, US], 8019 [ARIZ, MEXU, RSA, US]; Langille 20 [ARIZ]); Sierra Saguaribo (Fishbein 1352 [ARIZ]; Martin s.n. [ARIZ]); Cascada de Basaseáchic (Corral 2762 [NMC]; Martin s.n. [ARIZ]; Nesom 5443 [TEX]; Spellenberg 8446 [NMC]); Pinos Altos (Martin s.n. [ARIZ]); SE of Talayotes (Martin s.n. [ARIZ, MO]); SE of Cocheño (Martin s.n. [ARIZ, MO]); Sierra Obscura (Martin s.n. [ARIZ]); Arroyo Ocampo (Gurney s.n. [POM]); Nabogame (Laferrière 470 [MO, TEX], 1550 [MO], 1619 [ARIZ, MO], 1995 [ARIZ]).

Asclepias atroviolacea Woodson Photo
Slender, narrowed-leaved perennial herb; flowers yellow and reddish-purple, Jun-Aug. Known previously only from the type locality in Durango.
HABITAT: Meadows, rock outcrops; pine-oak forest. 1600-2150 m.
SPECIMENS SEEN: SONORA: Sierra Saguaribo, W of Saguaribo (Martin s.n. [ARIZ]); E of El Kípor (Fishbein 3612 [ARIZ]); Mesa El Campanero (Spellenberg 12,639 [NMC]). CHIHUAHUA: Cascada de Basaseáchic (Jenkins 89-166 [ARIZ]; Martin s.n. [ARIZ]; Van Devender 87-152 [ARIZ]); Río Basaseáchic (Barber s.n. [ARIZ]); Ocampo (Martin s.n. [ARIZ]).

Asclepias curassavica L. Photo Photo
Hierba de la cucaracha
Perennial herb to 75 cm, flowering the first year with striking red and yellow flowers, Dec-May, Aug. A pantropical weed perhaps native in the region.
HABITAT: Alkaline flats, irrigation ditches, disturbed sites, streamsides; thorn scrub, tropical deciduous forest, oak woods. 10-1150 m.
SPECIMENS SEEN: SONORA: Río Mayo, Hwy. 15 crossing (Sikes 179 [TEX]); W of Huatabampo (Martin s.n.[ARIZ]); SW of Navojoa (Sanders 8943 [UCR]); near Mayocahui (Sanders 8987 [UCR]; Van Devender 95-286 [ARIZ]); Sierra Saguaribo (Fishbein 217 [ARIZ]); N of Mamuncuera (Friedman 397-94 [ARIZ]). CHIHUAHUA: Río Tojiachi (Martin s.n [ARIZ]).

Asclepias elata Benth. Photo Photo
Coarse perennial herb to 1 m with glaucous leaves and pendant clusters of large green, white, and purple-brown flowers, Aug. Arizona, New Mexico, Texas, U.S. to Guatemala.
HABITAT: Slopes, fields; oak forest. 1000-1800 m.
SPECIMENS SEEN: CHIHUAHUA: Nabogame (Laferrière 662 [ARIZ, MO]).
Fruiting specimens are difficult to distinguish from A. glaucescens H.B.K. and A. mirifica Woodson and some collections assigned to those species may belong here.

Asclepias fournieri Woodson Photo Photo
Slender perennial herb to 20 cm, flowers cream and reddish-purple, May-Aug. Sonora, Chihuahua to Edo. de México, Hildago, México.
HABITAT: Grazed grassland, fields; pine-oak forest. 1200-1800 m.
SPECIMENS SEEN: SONORA: SW of Rancho Santa Bárbara (Martin s.n. [ARIZ]); Milpillas (Meyer s.n. [ARIZ]); Yécora (Fishbein 1740 [ARIZ]); E of Yécora (Fishbein 3660 [WS]); W of Maicoba (Fishbein 1760 [ARIZ, MEXU, MO]); El Kípor (Van Devender 95-364 [ARIZ]). CHIHUAHUA: Nabogame (Laferrière 471 [MO], 590 [A, MO], 1936 [A]); Bermudez (Van Devender 2007-647 [HPSU]).

Asclepias gentryi Standl. Photo Photo
"Low, erect, perennial herb 15-30 cm high, with a single or [multiple] stem. The flowers are very attractive, with an orange corona and red petals [Jul-Sep], very much like Asclepias curassavica, which has been cultivated as an ornamental." Sonora, Chihuahua to Nayarit, México.
The Río Mayo region is the northern limit of the range of this widely scattered and apparently rare species.
HABITAT: Open, grassy slopes, gravelly soil; oak forest. 900-1250 m.
SPECIMENS SEEN: SONORA: Sierra Saguaribo, Arroyo Gochico (Pennell 19,529 [US]); W of Maicoba (Fishbein 2508 [ARIZ], 3622 [WS]). CHIHUAHUA: Guasaremos (Gentry 1862 [ARIZ], 2330 type [ARIZ, ARIZ]).

Asclepias aff. glaucescens H.B.K. Photo Photo
Perennial herb to 50 cm; leaves narrow, glaucous; flowers green, yellow, and white, Jul-Aug. Sonora, Chihuahua, Coahuila, México to Costa Rica.
Apparently at the northwest limit of its range and rare in the region. The leaves in these specimens are unusually narrow and the shape of the corona is atypical. These collections may merit recognition as a distinct species or infraspecific taxon.
HABITAT: Field, pasture; pine-oak forest. 1540-1800 m.
SPECIMENS SEEN: SONORA: Yécora (Fishbein 1743 [ARIZ]); E of Yécora, N of Rancho El Trigo (Fishbein 3671 [ARIZ]). CHIHUAHUA: Nabogame (Laferrière 1684 [ARIZ]).

Asclepias hypoleuca (A.Gray) Woodson Photo Photo
Talayote
Perennial herb to 1 m, leaves velvety white beneath, flowers burgundy or dark maroon, Jun-Jul. Arizona, New Mexico, U.S., Sonora, Chihuahua, México.
A plant of the "sky island" mountain tops of the Arizona-Sonora border and the northern Sierra Madre Occidental. The Río Mayo region is the southern limit of its range, where it is apparently rare.
HABITAT: Hilltops, slopes and meadows; pine-oak forest. 2050-2300 m.
SPECIMENS SEEN: SONORA: Mesa El Campanero (Fishbein 1703 [ARIZ]; Martin s.n. [ARIZ]; Van Devender 2007-636 [HPSU]). CHIHUAHUA: Memelíchic (Gentry 2734 [ARIZ]); Pinos Altos (Ferguson s.n.[ARIZ]; Hewitt 130 [GH]); Pinos Altos-La Batería Rd. (Fishbein 1803 [ARIZ], Mahrt 162 [NMC]); Huajumar-Ocampo Rd. (Spellenberg 11,904 [NMC]); E of Cocheño (LeSueur 838 [TEX]).

Asclepias jaliscana B.L.Rob. Photo Photo
[Asclepias contrayerba Sessé & Moç.]
Perennial herb to 50 cm tall, herbage densely beset with stiff spreading hairs; flowers green and pinkish or yellow, Jul-Aug. Sonora, Chihuahua, México to El Salvador.
HABITAT: Grazed grassland, canyon bottoms, hillslopes; oak woods, pine-oak forest. 1300-1800 m.
SPECIMENS SEEN: SONORA: Yícora (Fishbein 1741 [ARIZ], 1860 [ARIZ, MEXU], 2493 [ARIZ, MEXU, MO], 3657 [HCIB, WS]; Van Devender 2003-921 [MISSA]); W of Rí Maicoba (Fishbein 1751 [ARIZ]); Sierra Saguaribo (Fishbein 1372 [ARIZ]; Martin s.n. [ARIZ], s.n. [ARIZ]). CHIHUAHUA: Sierra Saguaribo (Lehto 24,852 [ARIZ]); Nabogame (Laferrière 1528 [ARIZ]); SE of Talayotes (Martin s.n. [ARIZ]).

Asclepias jorgeana Fishbein & S.P. Lynch Photo Photo Photo
Perennial herb to 50 cm from fibrous rootstock, flowers green and lavender or white, Jun-Jul. Sonora, Chihuahua, Durango, Guanajuato, México.
HABITAT Arroyo bottoms, ravines, hillsides; pine-oak forest. 1900-2250 m.
SPECIMENS SEEN: SONORA: Mesa El Campanero (Van Devender 97-647 [ARIZ]). CHIHUAHUA: Cascada de Basaseáchic (Fishbein 1789 type [ARIZ, MEXU], Jenkins s.n. [ARIZ]; Spellenberg 9603 [NMC}); Pinos Altos (Ferguson s.n. [ARIZ], Hewitt 144 [GH]); NW of Pinos Altos (Ferguson s.n. [ARIZ]; Fishbein 1804 [ARIZ]); Arroyo Durazno, Las Baterías (Ferguson s.n. [ARIZ, MO]; Fishbein 1826 [ARIZ], Jenkins s.n. [ARIZ]).

Asclepias lemmonii A.Gray Photo Photo Photo
Robust perennial herb to 1.5 m tall, herbage with soft spreading hairs when young; leaves exceeding 25 cm long with parallel lateral veins; flowers cream turning pale yellow, Aug-Sep. Arizona, U.S. to Jalisco, México.
HABITAT: Open dry slopes, burned areas, grazed grassland; oak woods, pine-oak forest. 1200-2100 m.
SPECIMENS SEEN: SONORA: Sierra Saguaribo (Pennell 19,670 [US]); E of Yécora (Fishbein 1748 [ARIZ]); W of Arroyo Hondo (Ferguson s.n. [WS]); Sierra de Alamos (Fishbein 1919 [ARIZ]; Steinmann 93-336 [ARIZ]). CHIHUAHUA: Cascada de Basaseáchic (Spellenberg 9307 [MEXU, NMC]); near Talayotes (Martin s.n. [ARIZ]); Sierra Saguaribo (Martin s.n. [ARIZ]); Sierra Charuco (Langille 247 [ARIZ]).

Asclepias leptopus I.M.Johnst. Photo Photo
Sparsely-leaved, slender-stemmed, strongly fibrous herb to 50 cm with white flowers (May-Oct) and drooping fruits. Chihuahua, Sonora, Sinaloa, México.
HABITAT: Rock crevices in open woods and canyon bottoms; tropical deciduous forest, oak woods, pine-oak forest. 320-1800 m.
SPECIMENS SEEN: SONORA: San Bernardo (Gentry 1484 [ARIZ, F, MO]); Sierra de Alamos (Van Devender 94-793 [ARIZ]); S of R. Santa Bárbara (Jenkins 93-86 [ARIZ]); Río Mayo (Jenkins 91-83 [ARIZ]); Sierra Saguaribo (Fishbein 1457 [ARIZ], 2164 [ARIZ]; Martin s.n. [ARIZ]; Pennell 19,542 [US]); Río Cuchujaqui (Sanders 13,027 [TEX, UCR]; Starr 465 [ARIZ]; Van Devender 92-800 [ARIZ, UCR]); upper Río Cuchujaqui (Jenkins 91-50 [ARIZ]); Arroyo Santa Ana (Fishbein 3589 [WS]). CHIHUAHUA: Güisiego (Gentry 2388 [ARIZ, ARIZ]).

Asclepias linaria Cav. Photo Photo Photo
Yerba de cuervo
"Forms a low, spreading bush 5-10 dm high, with few or many stems from the base, [the long stems and needlelike leaves] suggestive of slender pine boughs." Flowers white, Mar-Sep. California, Arizona, New Mexico, U.S. to Oaxaca, Veracruz, México.
The most conspicuous and widely distributed of the milkweeds of the region.
HABITAT: Rock outcrops, canyon slopes and openings; pine-oak forest. 1200-2150 m.
SPECIMENS SEEN: SONORA: Sierra de Alamos (Steinmann 93-88 [ARIZ, UCR]); Mesa El Campanero (McLaughlin 534 [ARIZ]); Yécora (Van Devender 95-356 [ARIZ]); E of Yécora (Fishbein 1747 [ARIZ, MEXU]); W of Maicoba (Fishbein 1758 [ARIZ], 3606 [WS]). CHIHUAHUA: Sierra Charuco (Gentry 2306 [A, ARIZ, F, MEXU, MO, US], 8044 [ARIZ, RSA, US]; Langille 42 [ARIZ]); Los Cascarones (Gentry 2810 [ARIZ, MO]); E of Moris (Martin s.n. [ARIZ]); Arechuibo (Martin s.n. [ARIZ]); NW of Ocampo (Martin s.n. [ARIZ]); Concheño (Gurney s.n. [POM]); W of Pinos Altos (Hewitt s.n. [GH]); Nabogame (Laferrière 509 [ARIZ, MO], 1531 [MEXU, MO, TEX], 1928 [MEXU, MO], 2323 [ARIZ].

Asclepias mirifica Woodson Photo Photo
Palowisi nahcala (Guarijío)
Perennial herb to 1 m tall with broad glaucous leaves; flowers green, white and pale yellow, Jul-Oct. Known only from the Río Mayo region.
HABITAT: Canyon slopes and grazed openings; oak woods, pine-oak forest. 900-1800 m.
SPECIMENS SEEN: SONORA: Rancho Santa Bárbara (Jenkins 92-113 [ARIZ)); E of Yécora (Fishbein 2502 [ARIZ], 3666 [ARIZ]); W of Yécora (Reina 2000-412 [WS]); Río Maicoba (Fishbein 2520 [ARIZ]); W of Maicoba (Fishbein 1853 [ARIZ, MO], 3626 [ARIZ], 3627 [WS]); Maicoba (Pennington 315 [TEX]). CHIHUAHUA: Guasaremos (Gentry 2352 type [ARIZ, F], 2897 [ARIZ]); La Cieneguita (Gentry 2652 [ARIZ]).
Fruting specimens tentatively assigned here are also referable to A. elata.

Asclepias ovata M.Martens & Galeotti Photo
Inmortal grande
Perennial herb to 75 cm from fibrous root stock, flowers green and pinkish-yellow or white, Jul-Sep. Sonora, Chihuahua, Tamaulipas to Michoacán, Veracruz, México.
Apparently reaching its northern limit in the Río Mayo region.
HABITAT: Openings, fields, burns, seeps, canyon slopes and bottoms; oak woods, pine-oak forest. 1200-2100 m.
SPECIMENS SEEN: SONORA: Río Maicoba (Fishbein 1752 [ARIZ]); Sierra de Alamos (Fishbein 1915 [ARIZ], 1928 [ARIZ]; Steinmann 93-330 [ARIZ]); Rancho Santa Bárbara (Smith s.n. [ARIZ]); Sierra Saguaribo (Fishbein 1353 [ARIZ], 1426 [ARIZ]); Mesa El Campanero (Fishbein 3646 [WS]; Martin s.n. [ARIZ]); E of Maicoba (Fishbein 1835 [ARIZ], 1838 [ARIZ], 3621 [WS]; Martin s.n. [ARIZ], Reina 2000-384 [WS]); Mesa Grande (Martin s.n. [ARIZ]). CHIHUAHUA: Sierra Saguaribo (Burgess 5940 [ARIZ]; Martin s.n. [ARIZ]); Barranca Candameña (Spellenberg 9308[NMC]); near Ocampo (Martin s.n. [ARIZ]); Nabogame ( Laferrière 969 [MO], 981 [ARIZ, MEXU], 1524 [ARIZ, MEXU, MO], 1748 [MO], 2024 [MO]).

Asclepias quinquedentata A.Gray Photo Photo
Perennial herb to 15 cm; flowers cream and deep rose, Aug. Arizona, New Mexico, U.S. to San Luis Potosí, México.
Apparently rare in the region; a species more typically of the eastern slope of the Sierra Madre Occidental.
HABITAT: Oak forest. 1800 m.
SPECIMEN SEEN: CHIHUAHUA: Nabogame ( Laferrière 980 [MO]).
This record is based on an inadequate specimen, which is certainly of the affinity of this species.

Asclepias standleyi Woodson
Herbaceous perennial to 25 cm. Flowers green and white, Mar. Sonora, Sinaloa, México.
A rarely collected and little known species.
HABITAT: Yard in urban area, roadside; tropical deciduous forest. 350-900 m.
SPECIMENS SEEN: SONORA: Alamos (Van Devender 93-214 [ARIZ, UCR]); Sierra de Alamos, El Caracol (Fishbein 1989 [ARIZ]); Santa Ana (Van Devender 96-224 [ARIZ]).
The specimen from Santa Ana is intermediate to a more northern species, A. nyctaginifolia A. Gray, suggesting that these two species may intergrade.

Asclepias subaphylla Woodson Photo Photo Photo
Spreading to prostrate, nearly leafless shrub; flowers cream, yellowing with age, Sep-Mar. Narrowly distributed on the Gulf of California coast in Sinaloa and extreme southwestern Sonora, México.
HABITAT: Sand dunes in coastal thorn scurb. Sea level.
SPECIMENS SEEN: SONORA: Huatabampito (Fishbein 1978 [ARIZ, MEXU, MO], 2751 [ARIZ]; Lehto 19,646 [ARIZ]; Martin s.n. [ARIZ]; Van Devender 92-142 [ARIZ]; Webster 19,801 [RSA]); Estero Santa Bárbara (Martin s.n. [ARIZ], s.n. [ARIZ], s.n. [ARIZ]; Sanders 13,565 [UCR]; Fishbein 3824 [MEXU, MO, WS], 3825 [ARIZ, WS]); Punta Yavaros (Martin [ARIZ]; Fishbein 3820 [WS]); SE of Agiabampo (Friedman 018-96 [ARIZ]).

Asclepias subulata Decne. Photo Photo
Many-stemmed, nearly leafless shrub to 1 m. Flowers cream, aging yellow, year round. Nevada, U.S. to Baja California Sur, Sinaloa, México.
HABITAT: Calcareous clay soils in disturbed areas, weathered granite slopes; thorn scrub tropical deciduous forest. 30-720 m.
SPECIMENS SEEN: SONORA: Los Cerrillos (Gentry 14,397 [ARIZ]); Chinobampo (Gentry 2984 [ARIZ, MO]); Alamos-Navojoa Rd. (Chan s.n. [ARIZ]; Krizman s.n. [ARIZ]; Martin s.n. [ARIZ, MO]); Microondas La Luna (Martin s.n. [ARIZ]; Van Devender 93-340 [ARIZ]); SE of Piedras Verdes (Van Devender 94-78 [ARIZ]); Navojoa (Matuda 37,338 [LL, MO, TEX]; Waterfall 12,822 [ARIZ, MO, TEX]); Presa Mocúzari (Sanders 13,325 [UCR]; Van Devender 92-1379 [ARIZ, UCR]); Sierra de Alamos (Van Devender 95-154 [ARIZ]).

Cryptostegia grandiflora (Roxb.) R. Br. Photo
Bejuco
Liana or scandent shrub forming thickets to 4 m tall with large funnelform white flowers suffused with pink or lavender, Apr to Dec. Native to Madagascar (thanks to Jeff Ollerton for the correction).
"This species is commonly planted in the gardens of Alamos for its large, showy flowers, but has escaped cultivation and is now on its way growing up and down the arroyo running past the town. C. grandiflora is known to contain rubber and is reported to be poisonous to livestock."
HABITAT: Arroyo margins; tropical deciduous forest. 70-900 m.
SPECIMENS SEEN: SONORA: Alamos ( Chan s.n.[ARIZ]; Felger 5411 [ARIZ]; Freeland 2 [ARIZ]; Gentry 1663 [ARIZ, MO], 6775 [ARIZ], Sanders 605 [UCR]); Quiriego (Gentry 6768 [ARIZ]); Río Cuchujaqui (Gentry 6769 [ARIZ]; Starr 459 [ARIZ]; Van Devender 92-509 [ARIZ], 1165a [ARIZ]); Sierra de Alamos (Felger 5075 [ARIZ]; Quinn 62 [ARIZ]; Van Devender 95-152 [ARIZ], 95-280 [ARIZ]); Masiaca (Van Devender 95-308 [ARIZ]); Agiabampo (Friedman 338-94 [ARIZ]). CHIHUAHUA: El Cajón (Martin s.n. [ARIZ]).

Cynanchum ligulatum (Benth.) Woodson Photo Photo
[Mellichampia ligulata (Benth.) Vail, Cynanchum sinaloense (Brandegee) Woodson]
Panegua (Guarijío)
Robust perennial herbaceous vine, sometimes blanketing other vegetation; leaves large, cordate; flowers fragrant, white, turning yellow with age, Aug-Sep. Arizona, U.S. to Morelos, México.
HABITAT: Roadsides, arroyos, streamsides, valleys, mesas, slopes; tropical deciduous forest, oak woods, rarely pine-oak forest. 250-1600 m.
SPECIMENS SEEN: SONORA: San Bernardo (Gentry 1619 [ARIZ, MEXU]); Alamos (Sanders 1886 [MO, UCR]); Sierra de Alamos (Fishbein 1900 [ARIZ, MEXU], Martin s.n. [ARIZ]; Meyer s.n. [ARIZ, UCR]; Steinmann 962 [ARIZ]; Van Devender 92-988 [ARIZ), 94-514 [ARIZ], 94-779 [ARIZ]); Cerro Prieto (Sanders 9312 [RSA, UCR]); W of Agua Amarilla (Fishbein 3581 [MEXU, WS]; Van Devender 96-319 [ARIZ], 2000-480 [WS]); Mesa El Campanero (Reina 2000-536 [WS]); E of Maicoba (Reina 2000-363 [WS]); Microondas La Luna (Martin s.n. [ARIZ, MO]; Van Devender 94-1033 [ARIZ]); Sierra Saguaribo (Fishbein 1346 [ARIZ, MO], 1460 [ARIZ, MO]; Perrill 5246 [ARIZ]). CHIHUAHUA: Sierra Canelo (Gentry 2390 [ARIZ, F, GH, MEXU, MO, US]); Guasaremos (Gentry 2439 [ARIZ]); W of Ocampo (Mayfield 295 [MEXU]).

Dictyanthus altatensis (Brandegee) W.D. Stevens Photo Photo
[Matelea altatensis (Brandegee) Woodson]
Perennial vine, woody at base, with pale, yellow-green, dish-shaped flowers with reticulate markings (Aug); fruits covered with soft spines. Sonora and Sinaloa, México.
Apparently rare in Río Mayo region.
HABITAT: Valleys, saline soil on margin of warm springs; thorn scrub, tropical deciduous forest. 30-250 m.
SPECIMENS SEEN: SONORA: E of Huatabampo (Van Devender 93-269 [ARIZ, UCR], Fishbein 1308 [ARIZ]); Salitral (Martin s.n. [ARIZ]); S of Cd. Obregón (Sanders 1921 [UCR]); W of Teachive de Masiaca (Fishbein 3721 [ARIZ, MEXU, MO, WS]); Las Bocas (Martin s.n. [WS]; E of Las Bocas, Bachoco Rd. (Fishbein 2760 [ARIZ]).

Dictyanthus tuberosus B.L.Rob.
[Matelea tuberosa (B.L.Rob.) Woodson]
Scandent woody perennial; flowers bell-shaped, greenish with brown reticulations, Aug. Sonora to Jalisco, México.
Apparently rare in the region, where it has not been collected since the 1930s.
HABITAT: Granitic rock crevices. 750-900 m.
SPECIMENS SEEN: SONORA: Sierra de Alamos (Rose 12,863 [US]); Sierra Saguaribo, Arroyo Gochico (Pennell 19,544 [US])

Funastrum clausum (Jacq.) Schltr. Photo Photo
[Sarcostemma clausum (Jacq.) Roem. & Schult.; F. cumananse (H.B.K.) Schult.]
"A large vine trailing profusely over the marginal arroyo shrubs, as Celtis iguanea, Pisonia capitata, Hymenoclea monogyra, and Prosopis chilensis [P. glandulosa]. Hymenoptera and Lepidoptera visit the showy white flowers. Active through the summer rainy season." Leaves narrowly linear to broadly elliptic; flowers white to greenish cream, Jul-Oct. Sonora, México, Florida, U.S. to Argentina.
HABITAT: Arroyo margins, fields, along canals, canyons, streamsides; thorn scrub, tropical deciduous forest. 10-775 m.
SPECIMENS SEEN: SONORA: San Bernardo (Gentry 1308, 2286 [ARIZ, MO], 19,280 [ARIZ]); Sierra Saguaribo (Burgess 5942 [ARIZ]; Fishbein 1481 [ARIZ]; Martin s.n. [ARIZ]); Sierra de Alamos (Van Devender 92-952 [ARIZ, MO, UCR]); Boca del Río Mayo (Jenkins 88-103 [ARIZ]); N of Huatabampito (Sanders 9238 [ARIZ, UCR]); Río Cuchujaqui (Felger 189 [ARIZ]; Sanders 12,828 [UCR]; Soule s.n. [ARIZ]; Van Devender 92-708 [ARIZ]); N of Alamos (Cowan 5548 [UCR]); E of Camahuiroa (Sanders 12,756 [UCR]); SW of Navojoa (Sanders 8952 [UCR]); Teachive (Reina 96-571 [ARIZ]); W of Santa Ana (Van Devender 96-214 [ARIZ]); W of Tepoca (Reina 2000-488 [WS]).

Funastrum cynanchoides (Decne.) Schltr. var. hartwegii (Vail) Krings Photo
[Sarcostemma cynanchoides Decne. ssp. hartwegii (Vail) R.W.Holm; Funastrum hartwegii (Vail) Schltr.; Sarcostemma heterophyllum Engelm. sensu Torr; F. heterophyllum (Engelm. sensu Torr.) Standl.]
Huichori (Mayo), güirote lechosa
Perennial herbaceous vine, often densely cloaking other vegetation; flowers cream, usually suffused with livid purple, ciliate on the margins, Sep-Apr. The species ranges from California, Oklahoma, U.S. to Michoacán, Querétaro, México.
HABITAT: Arroyos, fields, streamsides, roadsides, coastal plain; thorn scrub, tropical deciduous forest. To 400 m.
SPECIMENS SEEN: SONORA: San Bernardo (Gentry 1308 [MO]); Río Cuchujaqui (Van Devender 92-199 [ARIZ], 94-282 [ARIZ]); Arroyo Guajaráy (Fishbein 1550 [ARIZ]); Alamos (Van Devender 93-216 [ARIZ]); N of Alamos (Fishbein 77 [ARIZ]; Van Devender 92-96 [ARIZ]); Alamos-Navojoa Rd. (Schiffman M-55 [UCR]; Tenorio 10,224 [MO, RSA]); N of Navojoa (Norris 20,075 [MO]); Arroyo Masiaca (Van Devender 93-946 [ARIZ]); S of Villa Juárez (Sanders 8975 [UCR]); S of Huatabampo (Fishbein 1974 [ARIZ]); Sierra Saguaribo (Fishbein 2132 [ARIZ, MEXU]); Sierra de Alamos (Fishbein 1971 [ARIZ]; Sanders 13,264.1 [UCR]); Camahuiroa (Van Devender 92-1099 [ARIZ, UCR]); E of Camahuiroa (Sanders 12,757 [UCR], 13,533 [UCR]); S of Masiaca (Breedlove 18,644 [RSA]).

Funastrum pannosum (Decne.) Schltr. Photo
[Sarcostemma pannosum Decne.]
Perennial herbaceous vine, becoming woody at base; leaves elliptic to cordate, bicolored due to velvety hairs beneath that are lost with age; flowers cream, Aug-Sep. Sonora, Chihuahua to Oaxaca, México.
HABITAT Slopes, arroyos, roadsides, mesas, altered soils, coastal plains; thorn scrub, tropical deciduous forest, oak woods (rarely pine-oak forest). 40-1000 m.
SPECIMENS SEEN: SONORA: Alamos (Fishbein 1482 [ARIZ]); E of Santa Ana (Goldberg 76-250 [ARIZ]); N of Nuri (Fishbein 3701 [ARIZ, HCIB, MEXU, MO, WS]); Agua Amarilla (Fishbein 2450 [ARIZ]); upper Río Cuchujaqui (Jenkins 88-278 [ARIZ]); Sierra de Alamos (Van Devender 93-62 [ARIZ, UCR]); Presa Alvaro Obregón (Reichenbacher 1462 [ARIZ]); E of Alamos (Fishbein 1596 [ARIZ], 1889 [ARIZ]); S of Alamos (Clarke s.n. [UCR]; Sanders 12,666 [ARIZ, UCR]); SE of Alamos (Cowan 5563 [UCR]); N of Alamos (Fishbein 1874 [ARIZ, MEXU, MO, UCR]; Van Devender 93-1250 [ARIZ]); S of Cd. Obregón (Sanders 1922 [UCR]); Sirebampo (Van Devender 95-1065 [ARIZ]); La Gacela (Van Devender 95-58 [ARIZ]); E of Camahuiroa (Van Devender 93-1282 [ARIZ]); N of Mesa Colorada (Felger 96-224 [ARIZ]). CHIHUAHUA: Guasaremos (Gentry 2369 [MO]).

Gonolobus gonoloboides (Greenm.) Woodson Photo
Coarse woody vine; leaves narrow, heart-shaped, hastate at base; flowers cream with green veiny markings (May-Aug); fruits with five prominently ridged angles. Sonora, Chihuahua, México.
Apparently uncommon throughout its limited range.
HABITAT: Steep slopes, altered soils; tropical deciduous forest, oak woods. 1050-1800 m.
SPECIMENS SEEN: SONORA: E of Rancho Santa Bárbara (Rondeau 90-45 [ARIZ, UCR]; Sierra Saguaribo (Lehto 24,773 [ARIZ]); Sierra de Alamos (Rose 13,067 [US]); W of Yécora (Reina 96-441 [ARIZ], 2000-428 [WS]; 2003-884 [MISSA]); W of Maicoba (Fishbein 1841 [ARIZ]); Trigo Moreno (Fishbein 3687 [ARIZ, MEXU, MO, WS]). CHIHUAHUA: SW of Ocampo (Martin s.n. [ARIZ]); Barranca Candameña (Mahrt 147 [NMC]).

Gonolobus aff. uniflorus H.B.K. Photo
Perennial vine growing high into trees; leaves heart shaped; flowers green with brown center, Jul; fruits large, winged. Known only from these collections.
HABITAT: Canyon bottoms, slopes; tropical deciduous forest, oak woods. 450-950 m.
SPECIMENS SEEN: SONORA: Sierra de Alamos: Cañón las Piedras (Van Devender 92-726 [ARIZ]), N of La Huerta (Van Devender 94-102 [ARIZ]); San Bernardo-Guajaráy Rd, N of Sejaqui (Fishbein 1965 [ARIZ], 3058 [WS]).
A marked northern extension of the range of the G. uniflorus complex of southern México and Central America; a distinct species, according to W.D. Stevens.

Macroscepis sp. nov. Photo Photo
Robust perennial vine with leaves narrowly heart-shaped at base and broader toward the tip; the entire plant clothed in long, reddish, spreading hairs.
HABITAT: Roadside, arroyo bottom; tropical deciduous forest. 275-525 m.
SPECIMENS SEEN: SONORA: N of Alamos, S of Los Tanques (Fishbein 2124 [ARIZ]); N of Güirocoba, Arroyo El Ojito (Fishbein 2177 [ARIZ], 3717 [ARIZ, WS], 4092 [ARIZ, WS], 4094 [ARIZ, MEXU, MO, WS]); Agua Caliente (Yetman s.n. [ARIZ]).
Known localities of Macroscepis are much further to the south (Jalisco, México to South America). The cited collections positively match specimens from Chamela, Jalisco, but it appears this species has never been named (fide W.D. Stevens).

Marsdenia edulis S.Watson Photo Photo
Batanene blanco, tonchi, mabem (Mayo), sispundam (Pima)
"A large, twining vine with tough, woody caudex 3-6 cm in diameter [and prominent corky wings]. It was observed climbing over Pachycereus pecten-aboriginium, Guazuma ulmifolia, and Lysiloma divaricatum. When well established over such trees, it throws a dense shade during the summer months, during which season it flowers and fruits. The fruits, however, do not ripen or mature until late fall. The tender green fruits are eaten by the natives." Flowers cream, fading yellowish, Jun-Aug. Sonora to Guerrero, México.
HABITAT: Arroyo margins, slopes, hillsides; thorn scurb, tropical deciduous forest. 50-400 m.
SPECIMENS SEEN: SONORA: San Bernardo (Gentry 1447 [ARIZ, MO], 1588 [ARIZ, MO]); Alamos-Navojoa Hwy. (Tenorio 3913 [MO], 4625 [MO, RSA]); Sierra Saguaribo (Fishbein 1088 [ARIZ]); Cerro de Bayájuri (Gentry 7952 [ARIZ]); N of Alamos (Sanders 8878 [ARIZ, RSA, UCR]); Masiaca (Van Devender 93-905 [ARIZ]); Río Cuchujaqui (Sanders 12,813 [UCR]); Onavas (Rea 1222 [ARIZ]); Sierra de Alamos (Van Devender 92-655 [ARIZ); NE of Navajoa (Martin s.n. [ARIZ, MO]); S of Navojoa (Barr 66-164 [ARIZ]); Camahuiroa (Sanders 12,751 [UCR]); E of Cd. Obregón (Fishbein 3703 [ARIZ, MEXU, MO, WS]; Stevens 2060 [MO]); Presa Alvaro Obregón (Reichenbacher 1453 [ARIZ]).

Matelea caudata (A.Gray) Woodson Photo Photo
[Vincetoxicum caudatum (A.Gray) Standl.]
Talayote
"A small perennial ground vine with many weak stems from the root crown lying on the ground or propped up against other herbs; not climbing, rather leafy and bushy. The native people sometimes eat the young fruits either raw or roasted." Fruits covered with stout soft spines. Flowers purple with green tips, Aug. Sonora, Chihuahua to Edo. de México, México.
Apparently rare in the region, where it has been only recently collected for the first time since the 1930s.
HABITAT: Valley bottoms; tropical deciduous forest. 200-800 m.
SPECIMENS SEEN: SONORA: San Bernardo (Gentry 1628 [ARIZ, ARIZ, MO]); Río Cuchujaqui (Van Devender 2002-1062A [ARIZ]; Fishbein 5436 [ARIZ, MISSA, MO]). CHIHUAHUA: Guasaremos (Gentry 2411, not seen).

Matelea chihuahuensis (A.Gray) Woodson
Decumbent perennial herb to 10 cm. Flowering Jul. Known only from Chihuahua, México and apparently rare in the region.
HABITAT Pine-oak forest. Ca. 2000 m.
SPECIMEN SEEN: CHIHUAHUA: Mesa de Basaseáchic (LeSueur 2009 [GH]).

Matelea petiolaris (A.Gray) Woodson Photo Photo Photo Photo
Huichuri (Mayo), mahoy piwalá (Guarijío)
Perennial vine, woody at base; leaves heart-shaped; flowers white to pale purplish-maroon, or occasionally greenish, corolla lobes narrowly lanceolate to linear, corolla tube long and narrow, Jul-Sep. "The Guarijíos are reported to toast the young [smooth] fruits over coals and eat them." Chihuahua, Sonora, Sinaloa, México.
Forms with flower color overlapping M. tristiflora are best distinguished by the long, narrow corolla tube concealing the anther-style head, and long, narrow corolla lobes.
HABITAT: Roadsides, valleys, slopes, canyons, arroyos; tropical deciduous forest. 200-850 (1570) m.
SPECIMENS SEEN: SONORA: San Bernardo ( Gentry 1573 [ARIZ, GH, MO], 1626A [ARIZ, GH, MO]; Pennell 19,726 [US]); Sierra Charuco (Gentry 2293 [ARIZ]); E of R. El Palmar (Fishbein 2449 [ARIZ]); N of Nuri (Fishbein 3700 [ARIZ, HCIB, MEXU, MO, RSA, WS]); S of Nuri (Fishbein 3702 [MO, WS]); W of Tepoca (Van Devender 2000-528 [WS]); N of Alamos (Fishbein 1873 [ARIZ, MEXU, MO, UCR]; Sanders 9463 [RSA, UCR]; Steinmann 968 [ARIZ]); Microondas La Luna (Sanders 9463 [UCR]); S of Alamos (Fishbein 3704 [ARIZ, MISSA, WS], 3714 [ARIZ, MISSA]; Clarke s.n. [RSA, UCR]; Cowan 5562 [UCR]); Sierra de Alamos (Rose 13,044 [US]; Van Devender 93-115 [ARIZ], 94-501 [ARIZ]); Sierra Saguaribo (Martin s.n. [ARIZ]; Lehto 24,733 [ARIZ]; Pennell 19,520 [US]); Río Cuchujaqui (Van Devender 94-887 [ARIZ]).
Fruiting specimens are nearly indistinguishable from M. tristiflora and are tentatively assigned here.

Matelea quercetorum (Standl.) W. D. Stevens Photo Photo
[Vincetoxicum quercetorum Standl.]
"A scandent perennial with an erect woody caudex about 1 m high, with white bark, about 1 cm in diameter; branches 1-2 m long, trailing on neighboring plants or rocks. Flowers [Jul-Sep]; petals olive green, bluish-purple in saucer, the petals finely reticulate-patterned." Sonora, Chihuahua, Sinaloa, México.
HABITAT: Rocky hillslopes, cliffs, canyons; tropical deciduous forest, oak woods. 1000-1400 m.
SPECIMENS SEEN: SONORA: Sierra Saguaribo (Fishbein 1423 [ARIZ], 1453 [ARIZ]; Martin s.n. [ARIZ]; Pennell 19,526 [GH, US)); Sierra Charuco (Gentry 1739 [ARIZ, MO], Dimmit 1002 [ARIZ]; Perrill 5245 [ARIZ]). CHIHUAHUA: Sierra Charuco (Gentry 2297 type, not seen, 2326, not seen); Guasaremos (Gentry 1561, not seen).

Matelea sepicola W. D. Stevens Photo
Woody based perennial vine with heart-shaped leaves; flowers small, in tight clusters, olive to brownish-green, Sep; fruits with soft spines similar to M. altatensis. Sonora to Jalisco, México.
The widely scattered localities known for this species, which reaches its northern limit in the region, suggest that it is rare throughout its range.
HABITAT: Fences, shrubs in canyon; tropical deciduous forest. 550-600 m.
SPECIMENS SEEN: SONORA: Arroyo El Cobre, near Choquincahui (Fishbein 2203 [ARIZ], 3056 [MO], 3059 [WS]; Van Devender 94-730 [ARIZ]).

Matelea tristiflora (Standl.) Woodson Photo Photo Photo Photo
Mahoy piwalá (Guarijío)
Woody vine, the stems usually not very long, with heart-shaped leaves. Flowers usually strikingly colored purplish-black, sometimes olive green, brown or an intermediate shade, sometimes emitting a foul scent; corolla lobes broadly lanceolate, corolla tube short and wide, Jul-Aug. "The Guarijío indians toast and eat the young, tender [smooth] fruits." Sonora, Chihuahua, México.
Easily confused with M. petiolaris, especially the greenish flowered forms; best distinguished by the relatively open corolla tube and short, broad corolla lobes.
HABITAT: Roadsides, slopes, canyons, valleys; tropical deciduos forest, oak woods. 400-1450 m.
SPECIMENS SEEN: SONORA: San Bernardo (Gentry 1626 [ARIZ, F, GH], 1629 [ARIZ, GH, MO]); Sierra Saguaribo (Fishbein 1339 [ARIZ], 1464 [ARIZ], 1875 [ARIZ]); Sierra de Alamos (Martin s.n. [ARIZ]); S of Alamos (Fishbein 3705 [ARIZ, MEXU, MISSA, WS], 3710 [ARIZ, MISSA, WS], 3711 [ARIZ, MISSA], 3712 [ARIZ, MISSA, WS], 3713 [ARIZ, MISSA] ), Sierra Charuco? (Perrill 5257 [ARIZ]); Choquincahui (Meyer s.n. [ARIZ]); W of Agua Amarilla (Van Devender 2000-518 [WS]); W of Tepoca (Van Devender 2000-527 [WS]); N of Tepoca (Búrquez 94-088 [ARIZ]); Mesa El Campanero (Reina 2000-540 [WS]). CHIHUAHUA: Guasaremos (Gentry 1560 not seen, 2327 [A], 2368, not seen, 2415 [F], type); NW of Moris (Jenkins 280-190 [ARIZ]).

Matelea sp. nov. aff. hastatula (Torr.) Woodson
Perennial vine, woody at base, with small arrow-shaped leaves; flowers tiny, white with ascending lobes (Sep, Dec); fruits smooth. Differing in the larger flowers and several details of floral morphology. Sonora, Sinaloa, México.
HABITAT: Coastal plain; thorn scrub. 50 m.
SPECIMENS SEEN: SONORA: SE of Las Bocas, near Sirebampo (Friedman 371-93 [ARIZ]); N of Teachive (Reina 96-573 [ARIZ]).

Matelea sp. nov. aff. parvifolia (Torr.) Woodson Photo Photo Photo
Perennial vine, woody at base, with sagitate leaves; flowers reddish-brown, very small with spreading lobes (Jan); fruits smooth with green and light grey stripes. Differing in the larger flowers and especially leaves and fruits, lack of fruit protuberances, and details of the floral corona. Known only from these collections.
HABITAT: Plain; coastal thorn scrub. 15-25 m.
SPECIMENS SEEN: SONORA: E of Las Bocas, Bachoco Rd. (Fishbein 2757 [ARIZ], 3723 [ARIZ, MEXU, MO, WS]; Friedman 138-95 [ARIZ]); near Camahuiroa, SW of Nescotahueca (Friedman 187-95 [ARIZ]); Sirebampo (Friedman 072-95 [ARIZ]).

Matelea sp. nov. aff. petiolaris (A.Gray) Woodson Photo
Perennial vine similar to M. petiolaris, but differing in the olive green flowers (Aug) with ragged-toothed corona segments. Sonora, Sinaloa, México.
HABITAT: Roadside in valley; tropical deciduous forest. 375 m.
SPECIMEN SEEN: SONORA: SE of Alamos, W of Arroyo El Potrero on road to Sabinito Sur (Fishbein 1886 [ARIZ, MO]).

Matelea sp. nov. aff. producta (Torr.) Woodson Photo Photo
Perennial vine, woody at base; flowers green, funnelform (Aug-Sep), differing from M. producta in the shape of the corona; fruits smooth. Known only from these collections.
HABITAT: Valleys, arroyos; thorn scrub. 75-250 m.
SPECIMENS SEEN: SONORA: N of Alamos, near Los Camotes (Jenkins 94-59 [ARIZ]); Teachive de Masiaca (Van Devender 94-668 [ARIZ]).

Metastelma contributed by Rachel Levin and Mark Fishbein

Metastelma arizonicum A.Gray Photo
[Cynanchum arizonicum (A.Gray) Shinners; M. watsonianum Standl.]
Caballito
Perennial herbaceous vine, leaves narrow; flowers white, Aug-Nov, Feb. Arizona, U.S., Sonora, probably Sinaloa, México.
HABITAT: Valleys, streamsides, disturbed areas; thorn scrub, tropical deciduous forest. 200-300 m.
SPECIMENS SEEN: SONORA: Arroyo Guajaráy (Gentry 1098 [ARIZ, F, GH, MO]); San Bernardo (Gentry 1298 [ARIZ, F, GH, MEXU, MO]); Sierra de Alamos (Rose 13,048 [US]; Van Devender 93-65 [ARIZ], 93-1310 [ARIZ]); E of Los Camotes (Fishbein 1878 [ARIZ]).

Metastelma californicum Benth. Photo
Perennial herbaceous vine twining on trees and shrubs on which they often form a dense covering; leaves narrowly ovate and slightly heart-shaped at the base; flowers reddish-green with dense, thick white hairs within (Dec-Feb); fruits reddish-green. Baja California, Baja California Sur, and disjunct along a narrow strip of coast in Sonora and Sinaloa, México.
HABITAT: Dunes in coastal thorn scrub. To 10 m.
SPECIMENS SEEN: SONORA: near Huatabampito (Fishbein 2750 [ARIZ], 2769 [ARIZ]; Martin s.n. [ARIZ]); Las Bocas (Van Devender 92-121 [ARIZ]).

Metastelma cuneatum Brandegee
Mostly herbaceous perennial vine becoming woody with age; leaves narrowly lanceolate to narrowly ovate, variable in size; flowers very small, white, Sep-Feb. Sonora, Sinaloa, México, perhaps further south.
HABITAT: Plains; coastal thorn scrub. To 25 m.
SPECIMENS SEEN: SONORA: near Las Bocas (Fishbein 2759 [ARIZ], 3724 [ARIZ, MEXU, MO, WS]; Friedman 150-95 [ARIZ]; Van Devender 92-133 [ARIZ], 94-698 [ARIZ]; Martin s.n. [WS]); near Camahuiroa (Friedman 284-94 [ARIZ], 015-95 [ARIZ],188-95 [ARIZ], 104-95 [ARIZ]; Van Devender 93-1253A [ARIZ], 93-1265 [ARIZ], 93-1284 [ARIZ]).

Metastelma latifolium Rose Photo
Woody vine, rarely with remarkably stout stems; leaves elliptic, flowers small, white, densely hairy within, Aug. Sonora, Chihuahua, México. Distribution outside the region unknown.
HABITAT: Ridges, mesas, slopes, roadsides; tropical deciduous forest, oak woods. 350-1500 m.
SPECIMENS SEEN: SONORA: Sierra de Alamos (Fishbein 1606 [ARIZ, USON], 1903 [ARIZ], 1905 [ARIZ]; Martin s.n. [ARIZ]; Palmer 1890-665 type [GH, GH, US]; Steinmann 955 [ARIZ]); Nuri-Tesopaco Rd. (Goldberg 76-322 [ARIZ] ); Sierra Saguaribo (Fishbein 1461 [ARIZ]; Lehto 24,882 [ARIZ]); Tepoca-Mesa El Campanero Hwy (Fishbein 2460 [ARIZ]). CHIHUAHUA: Guasaremos (Gentry 2373 [F, GH, MEXU, MO]).

Metastelma mexicanum (Brandegee) Fishbein & R.Levin
[Basistelma mexicanum (Brandegee) Bartlett, Cynanchum wigginsii Shinners]
Woody vine; leaves very narrow; flowers white (Aug); the style apex with a prominent knob. Arizona, New Mexico, U.S., Sonora, Sinaloa, México.
HABITAT: Mesas, slopes; tropical deciduous forest, oak woods, pine-oak forest. 900-1550 m.
SPECIMENS SEEN: SONORA: Sierra Saguaribo (Fishbein 1362 [ARIZ, MO], 1448 [ARIZ], Pennell 19,530 [US]); Sierra de Alamos (Steinmann s.n. [ARIZ]); SW of Rancho Santa Bárbara (Jenkins 93-88 [ARIZ, MEXU, MO, UCR, USON]).

Metastelma minutiflorum Wiggins
Perennial herbaceous vine becoming woody with age; leaves narrow; flowers very small, white, hairy within, Nov, Feb. Endemic to Sonora, México. Rare throughout its entire range.
HABITAT: Slopes, hills; thorn scrub, tropical deciduous forest. 200-450 m.
SPECIMENS SEEN: SONORA: near Piedras Verdes (Gentry 4857 [ARIZ, DS, MO, RSA]); Cerro Colorado (Gentry 5479).
Very similar to and perhaps only a low-elevation form of M. latifolium.

Metastelma aff. multiflorum. S.Watson
Woody vine; leaves narrow; flowers very small, white, Nov. Otherwise known from Jalisco to Oaxaca, México.
HABITAT: Steep slope; thorn scrub. 200 m.
SPECIMEN SEEN: SONORA: Mesa Masiaca (Steinmann 93-358 [ARIZ]).

Metastelma sp.
Perennial herbaceous vine; leaves linear to narrowly lanceolate, variable in size; flowers white, Sep.
HABITAT: Rocky slopes; thorn scrub. 100-400 m.
SPECIMENS SEEN: SONORA: Cerro Prieto (Sanders 9265 [ARIZ, MO]); Mesa Masiaca (Friedman 379-94 [ARIZ]).
We have been unable to match these collections, clearly of the same taxon, with any known Metastelma.

Pherotrichis aff. schaffneri A.Gray Photo Photo
Erect perennial herb to 30 cm tall with stiff, spreading hairs; flowers greenish and densely hairy within, Jul-Aug; fruits densely hairy. Sonora, Chihuahua, México to Central America.
Some of these specimens have been considered to represent an undescribed species in the unpublished thesis of L. Lozado P., however, I have not been able to observe the differences.
HABITAT: Canyons, flats, grazed grassland; oak woods, pine-oak forest. 1500-1900 m.
SPECIMENS SEEN: SONORA: Mesa Grande (Martin s.n. [ARIZ]); W of Maicoba (Fishbein 1759 [ARIZ, MEXU, MO], 1767 [ARIZ], 3623 [WS]); Yécora (Fishbein 1742 [ARIZ], 2494 [ARIZ]); E of Yécora (Fishbein 3670 [WS]); Mesa El Campanero (Fishbein 3654 [ARIZ]). CHIHUAHUA: Nabogame (Laferrière 500, 780 [MO]); Arroyo Durazno (Fishbein 1830 [ARIZ]; Martin s.n. [ARIZ]).

Coming soon: More Images, Keys

Mark Fishbein Home Page

Last modified February 2, 2009