Plant: Perennial herbaceous vine; stems with downward curving hairs; milky sap Leaves: lanceolate to mostly narrowly lanceolate to linear, hastate or sagittate to truncate at the base, attenuate to the apex, the margins (especially of younger leaves) more or less conspicuously undulate, 3-10 cm long, pubescent above, the midvein often whitened by a mat of hairs, the lower surface somewhat more sparsely hairy, the petioles 2-15 mm long INFLORESCENCE: UMBELS 4-10 flowered, the peduncles mostly 1-5 cm long, the pedicels with mostly curved or appressed hairs Flowers: 6-10 mm long; calyx lobes lanceolate-attenuate, 2.5-5 mm long, more than 3 times longer than wide, pubescent both outside and toward the tips inside; corolla broadly cup-shaped, green to purplish and pubescent outside, dark purple (rarely green), smooth and glabrous inside, or minutely hairy at the base of the crown ring, the tube ca. 2-3 mm long, the lobes oblong to ovate-elliptic, 5-9 mm long; crown ring free from the base of the vesicles, 0.6-1.1 mm high, the vesicles arising from the column ca. 1 mm above its union with the corolla tube, ca. 1.5 mm long in the upper portion, mostly as broad as or broader than long, flattened at the top and saccate below on the tangential surface, the lower portion constricted to a stalk-like base; column well developed, ca. 2 mm high beneath the anther wings, these 0.8-1 mm long; corpusculum ca. 0.25 mm long, the pollinia 0.7-0.9 mm long Fruit: FOLLICLES single, lanceolate-fusiform, long attenuate, 9-16 cm long Misc: 900-1600 m (2900-5200 ft); Apr-Aug REFERENCES: Sundell, Eric. 1994. Asclepiadaceae. J. Ariz. – Nev. Acad. Sci. Volume 27, 169-187.