Herbs, annual. Stem erect or spreading, sometimes woody at base, 10-60 cm tall, puberulent, glabrescent. Leaflets usually dimorphic, elliptic or oblong in lower part and lanceolate in upper part, 1-10 × 0.6-3 cm. Inflorescences terminal or leaf-opposed, laxly flowered; bracteoles absent. Pedicel 1-2 mm, with spreading hooked hairs. Calyx glumaceous, scarious, persistent, 4-lobed, with minute spreading hooked hairs and sparsely ciliate straight hairs; lobes not imbricate, subequal, narrowly triangular-ovate, 3-4 mm, ciliate, apex acuminate. Petals pink or reddish purple, subequal with calyx at anthesis. Legume (1-)4-6(-8)-jointed, (0.5-)1.5-2.2 cm × 1.8-2.3 mm, indehiscent, with dense minute hooked hairs, mostly without septa inside and with ridges at joint. Fl. Sep-Oct, fr. Sep-Dec.