M. Thulin, A.S. Hassan, & B.T. Styles (1993) Acacia 1: 368-384.

Plants trees 2.5-14 m tall; branchlets glabrous to tomentose. Leaves wuth stipular spines; stipular spines up to 8 cm long, straight or almost so, often deflexed; pinnae 2-14 pairs, each with (7-)12-27(-36) pairs of leaflets; leaflets 1.5-7 mm long, 0.5-1,5 mm wide. Inflorescences pedunculate, head-like racemes; peduncles up to 4.5 cm long; involucels located from near the peduncle base to about midlength, often subtending a few additional flowers.  Calyces  1-2 mm long; corollas bright yellow, 2.5-3.5 mm long. Pods straight or slightly curved, indehiscent, 8-17(-22) cm long, glabrous, pubescent, or tomentose, margins entire or more or less deeply constricted between the seeds; seeds  6.5-9 mm long, 5-8 mm wide, areoles 5-7 mm long. and 4-7 mm wide. 

Vachllia nilotica  (which is sometimes still called Acacia nilotica) is a widespread African species. It used to be much more abundant but has suffered severely from overuse in the last few decades. Link to the four subspecies Somaliland and Somalia.