Description from Flora of China
Perennial herbs, rhizomatous, pubescent to glabrescent. Stems decumbent or ascending, 20-50 cm, branches flexuous. Leaves palmately 3-foliolate, lower long petiolate, upper shortly petiolate; stipules linear-lanceolate, adnate to petiole for ca. 1/2 their length, free blade acuminately lanceolate; leaflets elliptic to broadly lanceolate, 15-55 × 6-20 mm, lateral veins 10-12, arching, branched, running into small marginal teeth, base rounded, margins entire to obscurely serrate, apex obtuse to acute. Flowers numerous, in globose to broadly ovate, terminal, solitary or paired, sessile or shortly pedunculate heads. Calyx 5-6 mm, veins 10; teeth subulate, unequal, lower tooth longest. Corolla purple, 15-18 mm; standard oblong-ovate. Legume ovoid. Seed 1, brown, angled. Fl. May-Jul, fr. Jun-Aug.
Cultivated, persisting after cultivation. Hebei, Shaanxi [native to SW Asia and Europe].