Description from Flora of China
Shrubs, much branched, 1-2 m tall. Branches glabrescent. Leaves 3-foliolate; petiole 2-4 cm; leaflet blade variable in shape and size, nearly ovate, ovate-lanceolate, ovate-elliptic, broadly ovate, rhombic, or orbicular-rhombic, 2-7 × 1.2-5 cm, base obliquely obtuse or cuneate, margin entire or shallowly undulate, apex usually acute to acuminate. Inflorescences 5-20 cm or longer, terminal ones mostly paniculate, axillary ones mostly racemose, often 2- or 3-flowered at each node. Calyx 3-4 mm, 4-lobed; lower calyx lobes longer or shorter than tube. Corolla purple or purple-red, 0.9-1.7 cm; standard broadly elliptic or obovate, base cuneate, apex slightly emarginate; wings and keel clawed, wings auriculate at base. Stamens 0.7-1.3 cm. Legume flat, linear, 3-5 × 0.4-0.5 cm, hairy, lower suture crenate, upper suture nearly straight, 4-6-jointed. 2n = 22.
Forest margins, forests, thickets, mountain slopes, rocky places, roadsides, ditches; 1000-4000 m. Gansu, NW Guizhou, SW Shaanxi, Sichuan, Xizang, Yunnan [Afghanistan, Bhutan, NE and SW India, Kashmir, Nepal, Pakistan].