A short lived, slightly hairy, decumbent or sometimes erect herb or under-shrub, 20-50 (-100) cm tall. Stipules 5-13 mm long, ciliate, persistent; petiole 2-5 mm long, with a slender stiped gland in upper third; rachis 3-4 cm long, glandless, produced into 2-3 mm long mucro. Leaflets 6-25 pairs, linear to linear-oblong, unequal-sided, the larger 7-13 mm long, 1.5-3 mm wide, glabrous, or with some hairs scattered near or on the midrib, with a rough often purple margin, top obli¬quely rounded, base very obliquely truncate, petiolules absent. Flowers 1-3, peduncle and pedicel c. 2.5-4 (-7) mm long, pubescent. Bracts c. 4 mm long, linear, caducous, acute. Bracteoles 2-3 mm long, acute. Sepals lanceolate, acute, 5-6 mm long. Petals very unequal, narrowly oblong to broadly orbicular and retuse, 3-5 mm long, narrowed towards the base, nearly clawed. Stamens 5, nearly equally deve¬loped. Ovary appressed tomentose, style glabrous, recurved, short, stigma trun¬cate, flat, peltate. Pods flat, thinly pilose, black, not glossy, dehiscent, 2-4.5 cm long, c. 3.5-5 mm across, strap-shaped, 6-16 seeded. Seeds light brown, glossy, smooth, flattened, rhomboid, 3 mm long.