Description from Flora of China
Herbs, annual or perennial, usually prostrate or decumbent. Stems slender. Stipules leaflike, spurred basally to point of insertion, basal portion usually divided. Leaves paripinnate, 2[-4]-foliolate; leaflets opposite, subsessile; leaflet blades usually pellucid punctate. Inflorescences axillary or terminal, sparse spikes; bracts usually peltate, stipulelike. Flowers small, usually enclosed in a pair of bracts. Bracteoles absent. Hypanthium short. Calyx small, 2-lipped, adaxial lobes short. Corolla usually yellow; petals ± equal. Stamens monadelphous; anthers dimorphic. Ovary linear, undulate, with 5-8 ovules; style filiform; stigma terminal. Legume a loment, compressed, not stipitate, smooth or surface echinate-setose, indehiscent, divided into few to many subglobose-oblate articles, abaxial suture straight, adaxial suture sinuate, apex usually without a beak. Seeds 1 to several, ovoid or reniform, compressed.
About 75 species: tropics and temperate regions worldwide; two species in China.