Senegalia nigrescens (Acacia nigrescens)
Acacia (Senegalia) nigrescens, the knob thorn, has a long cylindrical shape and rounded crown. It has knobs on the trunks and on branches with persistent thorns arising on the knobs. Thorns are in pairs below the leaves. Flowers appear before or with the new leaves making the tree very conspicuous. It prefers a heavy soil.