Vol. 79 No. 09 (2024): The South African Dental Journal

Knob thorn 
(Acacia nigrescens)
The knob thorn tree is characterised by the shape of its leaves. Each leaf comprises of four to six leaflets, is rather large with lopsided bases and double pinnately compound. The rachis bends backwards and has small spines. This tree is deciduous, losing its leaves in winter and early spring. New leaves can be bright red in colour. In some cases, individual species of knob thorn trees do not grow knobs on their branches or trunks. It ranges from 5 m to 18 m in height and is fire-resistant. The common name for the knob thorn tree in Afrikaans and English refers to its typically knobbed thorns.