Shrub 1-2 m high; young branchlets grey-or reddish-brown, glabrous. Leaves glabrous: petiole 2.2-4 cm long; rhachis 4-9 cm long, sulcate above, sometimes with minute scattered dark glands; pinnae (3)5-10(12) opposite or subopposite pairs; rhachillae (2.8)3.5-6(7) cm long; leaflets 20-40 pairs, 5-10 x 0.9-1.5 mm, linear or linear-oblong, sessile, glabrous, asymmetric basally, midrib starting in the distal corner of the leaflet-base and gradually becoming almost central in the leaflet, proximal side of base rounded, apex rounded or acute, nearly symmetric, lateral nerves not visible or inconspicuous beneath, sometimes with minute dark purplish glands at the base of the leaflets. Inflorescences racemose, racemes solitary, fascicled or aggregated on abbreviated lateral branchlets, 4-5.5 cm long (including the peduncle), glabrous. Flowers yellowish-white, pedicellate, pedicels 1.5-2 mm long, articulated near or below the middle, with minute dark reddish glands at the base of the pedicels. Calyx 0.75-1.25 mm long, 5-toothed, glabrous. Petals shortly united basally, 2-3 mm long, linear-oblong, glabrous. Stamens free among themselves, slightly adnate to the corolla basally; filaments 4-5 mm long; anthers with a deciduous apical gland. Ovary ±2 mm long, linear, glabrous. Pods dark brown or reddish-brown, 12-18 x 2-3.2 cm, oblong, straight or slightly curved, compressed, obscurely or prominently venose, at maturity the valves separating from the persistent margins. Seeds ±15 x 13 x 3.5 mm.
Shrub, up to 2 m high. Leaflets 0.9-1.5 mm wide. Racemes short, 40-55 mm long, usually aggregated on short lateral branchlets. Pods 120-180 x 20-32 mm. Flowers yellowish white.