Description from Flora of China
Woody climbing shrubs. Leaves pinnately 3-foliolate; stipules small, caducous; stipels persistent or deciduous. Panicles axillary or terminal. Flowers small and numerous, usually few clustered at nodes of rachis or branches; bracts and bracteoles small. Calyx campanulate or terete, usually with short teeth, 2-lipped; upper 2 teeth connate into entire or emarginate upper lip, lower lip with 3 teeth; teeth ovate, triangular, or lanceolate. Corolla exserted; petals all clawed; standard ovate or suborbicular, shorter than wings, base not appendaged, apex emarginate or lobed; wings oblong, obovate-oblong, or subspatulate, base sometimes auriculate, apex obtuse or rounded; keel shorter or longer than wings, nearly straight, base sometimes auriculate, apex obtuse. Stamens diadelphous; vexillary stamen free; anthers elliptic or suborbicular, equal in size or 5 larger and 5 smaller. Ovary shortly stipitate or sessile, 2-ovuled; style slightly incurved, glabrous or hairy; stigma small, terminal, capitate. Legumes sessile or stipitate, falcate or oblong, compressed, reticulate, densely puberulent or velutinous, thicker at top and 1-seeded, dehiscent only at seed bearing apex when mature, lower part indehiscent. Seed flat.
About 30 species: tropical Asia; ten species (seven endemic) in China.
(Authors: Chen Dezhao (陈德昭 Chen Te-chao), Zhang Dianxiang (张奠湘); Mats Thulin)