Description from Flora of China
Shrublets or perennial herbs. Stems erect or spreading, with sparse glandular trichomes. Stipules sheathlike, adnate to petiole, not spurred, persistent. Leaves pinnately 3-foliolate; leaflets subsessile. Inflorescences terminal or axillary spikes, with small clustered flowers; bracts membranous, persistent. Bracteoles lanceolate, membranous, persistent. Hypanthium long. Calyx tubular, 5-lobed; abaxial lobe narrow and distinct, adaxial 4 lobes connate. Corolla yellowish orange; standard orbicular, broadly ovate, or obovate, without an auricle, base narrowly cuneate, apex emarginate; wings oblong to obovate, shorter than standard, distinct, auriculate; keels similar to wings. Stamens 10, monadelphous, basal part closed or tubular; anthers dimorphic, alternate with longer 5 almost basifixed and shorter 5 dorsifixed. Ovary linear, sessile, with 2 or 3 ovules; style thin and straight; stigma terminal, calyptriform, extremely small. Legume a loment, oblong to ellipsoid, small, depressed, without a stipe, with coarse reticulate veins, often tuberculate, with 1 or 2 articles, indehiscent, apex with a beak. Seeds ovoid or reniform; hilum usually oblique, with a prominent radicle lobe.
About 25 species: tropical and subtropical Africa, America, and Asia; two species (both introduced) in China.