Plant: perennial herb; stems erect, unbranched, 50-180 cm tall, densely short wooly when young, soon glabrate; milky sap Leaves: opposite, sessile or the petioles to 2 mm, the blades broadly lanceolate to mostly ovate, 4-25 cm long, 3-11 cm broad, rounded to shallowly cordate and more or less clasping at the base, attenuate to an acute apex, densely short woolly when young, in age more or less glabrate on both surfaces, the margins erose INFLORESCENCE: UMBELS lateral to subterminal at the upper nodes, 5-8 cm broad, the peduncles 2-13 cm long, the pedicels wooly Flowers: large; calyx lobes ca. 3-4 mm long; corolla greenish, the lobes 6-9 mm long; hoods greenish white to yellow-brown, erect-ascending, obovoid-triangular, widening upward to a truncate apex, 3.5-5 mm long along the dorsal surface, 2.5-5 mm broad at the top, about as long as the gynostegium, the horns radially flat, attached to about the middle of the hoods, sickle-shaped, exserted ca. 2 mm to the center of the stigma head; anther wings 2-2.8 mm long; corpusculum ca. 0.4 mm long, the pollinia 1.4-1.5 mm long Fruit: follicles erect on deflexed pedicels, 7-9 cm long Misc: Washes and roadsides in desert scrub communities; 50-1500 m (200-5000 ft); Apr-Oct REFERENCES: Sundell, Eric. 1994. Asclepiadaceae. J. Ariz. - Nev. Acad. Sci. Volume 27, 169-187.