Description from Flora of China
Climbing shrubs. Branchlets blackish brown, with sparse lenticels; branchlets, petioles, petiolules, and inflorescences hirsute with ferruginous hairs. Stipels subulate, ca. 2.5 mm; terminal leaflet obovate or broadly elliptic, 3-13 × 3-8.6 cm, lateral ones slightly smaller, ovate or oblong, subleathery, ferruginous hirsute abaxially, subglabrous adaxially, lateral veins 5-7 pairs, slightly curved, veinlets reticulate, base rounded, asymmetric, apex rounded or with short blunt mucro. Panicles with congested flowers; bracts and bracteoles persistent; bracteoles narrowly lanceolate, ca. 1.5 mm. Calyx 5-5.5 mm; teeth as long as tube or nearly so, 2-2.7 mm, upper ovate, apex slightly acute, lower 3 lanceolate, apex long acuminate, middle one longest. Corolla white; standard suborbicular, ca. 5.5 × 5 mm, apex emarginate, base cuneate, claw 3-3.5 mm; wings obovate-oblong, 4.5-5 mm, base with acute auricle ca. 1 mm on one side, other side without auricle or occasionally with slightly obtuse auricle, claw 3-3.5 mm; keel oblong, ca. 4 mm, slightly curved at back, base with a broad and acute auricle ca. 0.5 mm on one side, claw ca. 3.5 mm. Anthers subglobose, equal in size. Ovary sessile, ferruginous hirsute. Legumes falcate, 7.5-9.5 cm, base rounded and incurved, upper part attenuate to a slightly curved beak. Seed oblong, immature. Fl. Jan-Feb, fr. May-Jun.
● Open forests, mountain slopes, valleys, near roads, often climbing on trees; 700-1600 m. SW Yunnan.