Plants shrubs or trees 3-30 m tall, sometimes scandent; branchlets glabrous to puberulent, pubescent or, less often, pilose. Prickles usually presentbelow the stipules, 1, 2 or 3, sometimes reduced or absent, short, more or less hooked. Leaves petiolate, stipulate, evenly twice-pinnate: stipules not spinescent; petioles sometimes with a gland; pinnae 1-10(-18) pairs, each with 2-15(-27) pairs of leaflets. Inflorescences usually spicate but sometimes capitate and pedunculate, spikes up to 1.8-12 cm long. Flowers small; calyces united, 2-3mm long; corollas usually white, cream or yellow, sometimes pinkish. Pods ovate to elongate, 3-30 cm long, 0.9-5 cm wide, usually straight, dehiscent.
Senegalia includes 150-200 species. A count needs to be made and there are some species still included in Acacia that probably need to be transferred. Morphologically, it is very similar to Vachellia, one of the other genera recently segregated from Acacia. Senegalia differs primarily in not having spinescent stipules and almost always having prockles.