Senegalia nigrescens leaves getting old

Old leaves of Senegalia nigrescens become slightly yellowed, damaged and tired looking towards the end of the season when temperatures drop by late autumn or winter. These in picture are no exception. They were photographed in mid-July east of Acornhoek.

The knob thorn is a deciduous tree, usually leafless for several months before the spring temperatures rise, or better: some rain will bring about fresh sprouting of a leaf covering on the young branchlets. Transversely elongated lenticels, whitish in colour, are found on the young stems of S. nigrescens trees among leaf nodes and spines (Carr, 1976; Coates Palgrave, 2002).