Description from Flora of China
Subshrubs or perennial herbs. Roots and rhizomes very developed. Stem erect, much branched. Leaves imparipinnate, (3 or)5-17-foliolate; stipules 2, free, caducous or persistent; leaflets entire or serrulate. Racemes axillary; bracts caducous. Calyx campanulate or cylindric, 5-toothed, slightly bilabiate. Corolla white, yellow, purple, or purple-red; standard shortly clawed; wings shorter than standard, obliquely oblong; keels joined. Stamens diadelphous or monadelphous. Ovary sessile, 2-10-ovuled. Legume ovoid, oblong, or linear, rarely moniliform, straight or curved, flat or inflated, prickly or rarely smooth, indehiscent or dehiscent. Seeds reniform or orbicular.
About 20 species: mainly in Asia and Europe, extending to Australia, and in North and South America; eight species (two endemic) in China.
(Authors: Bao Bojian (包伯坚); Kai Larsen)