Vines fetid; branches to 3 m, harshly strigose; tendrils usually branched from 1–5 cm beyond base. Leaves: petiole 3–7 cm; blade 8–15 cm wide, surfaces moderately to densely white-sericeous abaxially, glabrous adaxially. Inflorescences: staminate flowers in long-pedunculate racemes; pistillate flowers in loose fascicles; peduncle erect, 1–2 cm in flower, 6–9 cm in fruit. Flowers: hypanthium 10–18 mm; sepals erect, not recurving. Pepos 6–10 cm. Seeds light brown, 9–12 mm. 2n = 28.

Flowering May–Sep. Roadsides, gravelly stream terraces, interfan alluvium, dunes, flats, rocky slopes, lava beds, grasslands, creosote scrub, Chihuahuan desert scrub of Flourensia-Larrea, mesquite, oak chaparral, oak-juniper woodlands; 800–1700 m; Ariz., N.Mex., Tex.; Mexico (Chihuahua, Coahuila, Durango, Sonora).