Description from Flora of China
Erect shrubs, subshrubs, or woody or herbaceous vines. Leaves pinnately or sometimes digitately 3-foliolate; stipules and stipels small or absent; leaflets usually with sessile glands abaxially. Inflorescence axillary or terminal, racemose. Bracts deciduous; bracteoles absent. Calyx campanulate, 5-lobed; lobes short, upper 2 connate or slightly lobed at apex. Standard almost circular, obovate or obovate-elliptic, base clawed, with inflexed auricles; wings narrowly to broadly elliptic, auriculate; keels obliquely circular, apex obtuse. Stamens diadelphous; vexillary stamen free; anthers uniform. Ovary almost sessile; ovules 2-6; styles long, linear, apex curved, upper part glabrous or slightly hairy; stigma terminal, small, capitate. Legume linear-oblong, dehiscent, compressed. Seeds 2-10, reniform to almost orbicular, colorful or blotched; strophiole obvious or absent.
See Maesen, Wageningen Agric. Univ. Pap. 85(4): 1-225. 1985.
About 30 species: tropical Asia, Madagascar, Oceania; seven species in China.
(Authors: Sa Ren (萨仁); Michael G. Gilbert)