Description from Flora of China
Climbing shrubs. Branchlets strigose when young, glabrescent. Petiole 6-9 cm; stipels subulate, 5-7 mm; petiolules 4-5 mm; leaflets subequal, obovate, 7-13 × 4-6.5 cm, leathery, puberulent and strigose along veins abaxially, sparsely strigose adaxially, lateral veins 8 or 9 pairs, straight or arched toward margin, raised on both surfaces, veinlets reticulate, base broadly cuneate or obtuse, apex subtruncate, mucronate, strigose. Panicles axillary or terminal, 15-20 cm; rachis and pedicels puberulent; bracts caducous; bracteoles linear, ca. 1 mm; pedicels 3.5-4.5 mm, slightly shorter than calyx. Calyx 5-5.5 mm, puberulent on both sides; upper 2 teeth ± connate, lower 3 ovate-lanceolate, 2.5-2.7 mm. Corolla purple; standard orbicular, ca. 7 mm in diam., apex emarginate, base cuneate, claw ca. 2 mm; wings subspatulate, 5-5.5 mm, apex 3-3.5 mm wide, base with obtuse auricle on one side, claw 4.5-5 mm; keel oblong or slightly broadened in upper part, 3.5-4 mm, curved and slightly connate at back, apex rounded, with obtuse auricle on one side, claw ca. 4.5 mm. Anthers globose, 5 larger and 5 smaller. Ovary narrowly oblong, ca. 4.5 mm, puberulent; style hairy. Legumes 6-9 cm, apex slightly narrowed and curved, with short acute beak, not stipitate. Fl. spring.
Forests, mountain slopes; ca. 1600 m. Yunnan (Simao) [Myanmar, Thailand].