Senegalia nigrescens young stem

A young knob thorn stem may look like this. The knobs are sparsely scattered upon the pale, flaky and fissuring stem that is bare and erect.

One day when this tree is big and old, the lower stem identification tell-tales will have shifted up; the knob thorn losing its knobs entirely lower down or nearly so. But stem section higher up, not too near the tips should present these hallmark knobs of the species; nice big ones visible from below.

This tree was seen in the Sabi Sand Game Reserve (Carr, 1976; Coates Palgrave, 2002).