Plant: Perennial herbaceous vine, irsute to pubescent, twining vines from a woody base, the hairs mixed with shorter, glandular, mostly yellow- to brown-tipped trichomes; milky sap Leaves: cordate to subhastate, more or less abruptly narrowed to an attenuate tip, 1-9 cm long; petioles 1-3 cm long, shorter than the blades INFLORESCENCE: umbelliform, the peduncles tardily elongating to 3 cm. Flowers: ca. 1 cm long; calyx lobes ca. 3 mm long, half as long as the corolla tube; corolla greenish yellow, pubescent outside, glabrous inside, cylindric-campanulate, the tube 4-7 mm long, the lobes oblong, erect, about as long as the tube, the tips spreading; crown included deep within the corolla tube and arising from it, cup-shaped, 1-2 mm long, about as long as the stigma head, the rim entire and undulate to mostly notched opposite the corpuscula, the inner surface with 5 fleshy protuberances opposite the anthers; gynostegium subsessile, the anther head disk-shaped, the anther wings ca. 0.25 mm long; corpusculum 0.2-0.3 mm long, the pollinia horizontal from the translator arms, deltoid to oblong-quadrate, ca. 0.4 mm across; stigma head apically flat, depressed in the center Fruit: FOLLICLES 9-12 cm long, glabrous Misc: Desert grasslands, chaparral, alluvial thickets, mts; 900-1700 m (3000-5500 ft); May-Aug REFERENCES: Sundell, Eric. 1994. Asclepiadaceae. J. Ariz. - Nev. Acad. Sci. Volume 27, 169-187.