Description from Flora of China
Herbs, rarely shrublets or shrubs. Stipules 2, opposite petiole, scarious, connate or free, marcescent or deciduous. Leaves imparipinnate; leaflet blades opposite, margin entire. Racemes axillary, lax to capitate; bracts marcescent or caducous. Bracteoles 2, at base of calyx. Calyx campanulate to obliquely campanulate; teeth 5, ± equal or unequal. Corolla purple, pink, yellow, or white; standard usually longer than wings, shorter or rarely as long as or longer than keel, turned backward at anthesis; keel with claw half or less than half as long as lamina. Stamens diadelphous (9+1). Ovary sessile to stipitate, with a few ovules. Legume articulate, usually divided into several articles, indehiscent, sutures connate or winged; articles compressed to biconvex, with veins, ribs, bristles, or spines, margin usually distinct.
About 160 species: N Africa, Asia, Europe, North America; 41 species (17 endemic) in China.
(Authors: Xu Langran (徐朗然 Xu Lang-rang); Byoung-Hee Choi)