Plants trees 4-21 m tall; crown usually flat. Branchlets glabrous to densely pubesent when young. Leaves with stipules; stipules thorny, of mixed length and shape, some up to 5 mm long and hooked others up to 100 mm long and straight; blades bipinnately compound, with 2-10 pairs of pinnae; pinnae with 6-22 pairs of leaflets; leaflets 0.5-4(6) mm long, 0.5-1 mm wide. Inflorescences pedunculate heads; peduncles 0.4-2.4 cm long, involucel present on lower half. Flowers radially symmetric; calyx 1-2 mm long; corolla whitish, 1.5-2.5 mm long. Fruits legumes, legumes 6-10 (13) mm wide, usually contorted or spirally twisted, rarely almost straight; indehiscent or very slowly dehiscent; longitudinally veined; glabrous or hairy; glandular or not. Seeds 4-7 mm long, 3-6 mm wide, compressed; areoles 3-6 mm long, 2-4 mm wide. Taxonomic comment: In their discussion of Acacia tortilis in Somaliland and Somalia, Thulin et al. indicate that further taxonomic research is needed to clarify its infraspecific taxonomy.
