Annual herb with slender, suberect glabrous or obscurely downy stems; leaf rachis terminating in short tendril, leaflets 8-12, upper leaves about 2-3 cm long, ligulate, lower shorter and broader; stipules small, obliquely lanceolate, deeply toothed; flowers solitary or paired, not racemed, pink to purple; calyx teeth lanceolate-subulate; corolla red or blue, twice as the calyx; stamens 10, diadelphous, mouth of staminal sheath very oblique, anther uniform; ovary nearly sessile, ovules 2-many; style short, filiform, stigma capitate; pods linear-oblong, recurved, glabrescent, flattened, 6-10 seeded, dehiscent.