Description from Flora of China
Herbs, perennial or rarely annual, often suffrutescent, usually sericeous. Stipules caducous. Leaves imparipinnate; stipels absent; leaflet blades opposite, abaxially often sericeous, secondary veins to ca. 30 on each side of midvein and closely parallel, margin entire. Pseudoracemes terminal or axillary, sometimes opposite a leaf; bracts usually caducous. Bracteoles absent. Corolla white, cream-colored, or mauve, occasionally orange or red; standard reflexed, suborbicular, outside villous or sericeous. Stamens monadelphous; vexillary stamen somewhat distinct from other 9. Ovary sessile, with trichomes, with numerous ovules. Legume flat, occasionally inflated, dehiscent, apex often beaked; valves twisted. Seeds 5-16 per legume, oblong, ellipsoid, or occasionally globose; radicle folded.
More than 400 species: tropical and subtropical regions of the world; 11 species (one endemic, three introduced) in China.
(Authors: Wei Zhi (韦直); Les Pedley)