Common Characteristics of Alysicarpus
Herbs, perennial. Stems erect of diffuse, branched. Leaves 1-foliate, rarely pinnately 3-foliate, stipulate and stipellate; stipules scarious or nearly leathery, free or connate. Racemes axillary or terminal; flowers small, mostly ca. 5 mm, usually binate at each node of rachis; bracts scarious, early deciduous. Calyx 4-lobed; lobes dry, rigid, nearly equal, upper lobe 2-toothed at apex. Corolla not or slightly longer than calyx; standard broad, obovate or nearly orbicular; keel obtuse, adherent to wings. Stamens diadelphous (9+1); anthers uniform. Ovary sessile or nearly so, many ovuled; style linear, incurved; stigma capitate. Legume cylindric, swollen, many jointed, 1-seeded per article, indehiscent. 
There are 3 species in Thaiand.