Plant: perennial vine, Densely hirsute to pilose, twining vines, the long straight hairs mixed with shorter, glandular, typically white-tipped trichomes; milky sap Leaves: cordate, the apex attenuate to abruptly apiculate, 3-9 cm long; petioles 2-7 cm long, mostly somewhat shorter than the blades INFLORESCENCE: irregularly cymose, from umbelliform to racemose-paniculate, the peduncles tardily elongating to 2-5 cm Flowers: ca. 1-2 cm long; calyx lobes 4-6 mm long, about equal to the corolla tube or slightly shorter; corolla white or tinged with green or light rose, sparsely short-hairy on the tube outside, glabrous inside, rotate-ascending, the tube ca. 3-5 mm long, the lobes oblong, spreading-erect, 7-13 mm long, mostly about twice as long as the tube; crown included within the corolla tube, arising from the column, of 5 distinct, fleshy, rectangular-saccate segments opposite and appressed to the anthers, ca. 0.5-1 mm high, 1-2 mm broad, about as long as the anther head, apically truncate and bidentate to erose toward the middle, the margins more or less folded inward; gynostegium scarcely elevated, the column 0.5-1 mm high, the anther head disk-shaped, the anther wings indistinct; corpusculum 0.1-0.2 mm long, the pollinia pendulous from the sharply bent translator arms, obovate, 0.4-0.5 mm long; stigma head apically projected 1-2 mm into a fluted column capped by an irregularly crested knob Fruit: FOLLICLES 10-13 cm long, glabrous Misc: 1500 m (5000 ft); Aug-Nov REFERENCES: Sundell, Eric. 1994. Asclepiadaceae. J. Ariz. - Nev. Acad. Sci. Volume 27, 169-187.