Acacia seyal
A tree 7 - 10 meters tall, with prominent whitish, smooth-barked branches and trunk. Crown of horizontally spreading, flattened layers. Young branches green, becoming reddish-brown, the bark peeling off in older branches revealing a powdery layer (the creamy-white powder comes off on rubbing, exposing a lower green bark): bark on older branches and trunk, reportedly, sloughed off as very thin papery layers every year. Spines stipular, paired, small to very small in mature trees, about 1 cm in length or smaller, fused at base or separate, rarely (in our material) more or less swollen to form very small "ant-galls": spines large on new lower branches and up to 8 cm long. Leaves petiolate, with 1 to 6 (reportedly up to 8) pinna-pairs : leaflets 12-20 pairs (reported range 7 - 20 pairs) per pinna, up to 6 mm long, 2 mm wide, glabrous, minutely papillate, ciliate-margined, more or less oblique- based. Petiole up to 1 cm long, with a prominent gland : rachis up to 3.5 cm (reportedly up to 7 cm) long, with a gland between the last pinna-pair, and projecting beyond the last pinnae as a small, flat triangular, sharp-pointed structure : rachillae up to about 3.5 cm long. Flowers in pedunculate, axillary, fascicled heads on new, terminal or short axillary shoots. Heads golden-yellow, about 1.5 cm across : involucel usually below the middle of the peduncle. Calyx cupulate, 5-dentate, about 2.5 mm long. Corolla 5-lobed, about 5 mm long. Pods falcate, flat, more or less constricted between the seeds, abruptly narrowed towards the apex, narrowly margined, straw-colored, glabrous, finely longitudinally veined, up to 20 cm long, 7 mm wide. The pods resemble those of A.
ehrenbergiana in shape and like them hang in clusters on the plants.