Tree or shrub with straight, finely grey downy branches; stipular spines straight, about 2 cm long, white, sharp; leaves alternate, 4-7 cm long; rachis grey pubescent, generally with several glands between the first and few terminal pairs of pinnae; pinnae 2-10 pairs, pinnules 7-25 pairs; leaflets subsessile, elliptic, glabrous, membranous, obtuse, entire, nerves obscure; flowers in globose heads, yellow, 2 cm across, in axillary clusters, peduncle densely grey downy, about 50 flowers in each head; 2 bracts above the middle of peduncle, subtending leaves of upper nodes; calyx 5-toothed, glabrous, campanulate; corolla 5-toothed, bright yellow, glabrous, twice the length of calyx; stamens many, free, much exserted; ovary stipitate, terete, style short, slender, stigma simple; pod stipitate, subindehiscent, 8-12 seeded, glaucous, rigidly, coriaceous, densely, persistently grey downy, moniliform, deeply indented between; seeds globose, apex beaked.