Description from Flora of China
Bryonia pedunculosa Seringe in Candolle, Prodr. 3: 306. 1828; Herpetospermum caudigerum Wallich ex Chakravarty; H. grandiflorum Cogniaux.
Stem and branches slender, puberulent at first. Petiole 4-8(-10) cm; leaf blade ovate-cordate, 6-12 × 4-9 cm, membranous, both surfaces scabrous, yellow-brown pubescent at first, base cordate, margin dentate, apex caudate-acuminate. Male flowers usually in a raceme or solitary; inflorescence 12-40 cm, 5-10-flowered, puberulent; calyx tube 20-25 cm, apex 8-9 mm in diam.; segments linear, 8-9 mm; corolla yellow; segments elliptic, 20-22 × 12-15 mm; filaments 2-3 mm; anthers 5-6 mm; rudimentary ovary subulate, 4-5 mm. Female flowers: calyx tube narrowly tubular, ca. 15 mm, densely yellow pubescent; segments linear, ca. 9 mm; corolla segments oblong, 20-25 × 15-20 mm; ovary oblong-ovoid, densely yellow hispid. Fruit 7-8 × 3-4 cm, fibrous. Seeds pale gray, oblong, ca. 12 × 5 mm, 2-3 mm thick, base truncate. Fl. and fr. Jun-Oct.
Thickets and forest margins on mountain slopes; 2300-2500 m. Xizang, Yunnan [Bhutan, India, Nepal].