Description from Flora of China
Glycine viscosa Roth, Nov. Pl. Sp. 349. 1821.
Herbs. Stems twining, robust and slightly woody, densely gray viscous pubescent and with sticky glandular hairs. Leaves pinnately 3-foliolate; stipules small, usually lanceolate, 5-8 mm, pubescent, always persistent; petiole 4-9 cm, densely pubescent and with sticky glandular hairs; petiolules 1.6-2.5 cm; leaflets papery; terminal leaflet broadly elliptic or rhomboid-elliptic, 5-8 × 3.5-5 cm, both surfaces villous, abaxial surface with dense small yellow-brown sessile glands, basal veins 3, lateral veins 3-5 pairs, base rounded, apex usually acute, caudate-acuminate; lateral leaflets obliquely ovate to obliquely elliptic. Racemes solitary or a few clustered in axil, 7-22 cm; peduncle 2.8-3.9 cm, densely villous and glandular hairy. Calyx ca. 8 mm, exterior with glands; upper lobes triangular. Corolla ca. 2 × as long as calyx. Legume oblong, ca. 2 × 1 cm, pubescent, straight, apex with small beak, narrowed to both ends. Seeds 2, black, reniform, ca. 5 × 4 mm. 2n = 22.
The Chinese material belongs to Rhynchosia viscosa var. viscosa. Verdcourt (Kew Bull. 25: 82-86. 1971) recognized three further varieties, all almost entirely restricted to Africa.
Roadsides. Yunnan [India, Indonesia, Malaysia, Nepal, Sri Lanka, Thailand; Africa (widespread), Madagascar].