A small to medium sized slow growing tree with an umbrella shaped canopy. It has both straight and hooked thorns to help protect its highly nutritious leaves and pods from herbivores. These drought resistant trees occur in deciduous woodland, bushveld and grassveld.
The roots of the umbrella thorn are used to make spear shafts, fishing spears and frameworks for temporary shelters.
The thorny branches of the umbrella thorn are used to make temporary enclosures to keep livestock in and wild animals out.
The Afrikaans name for the umbrella thorn is Hook-en-steek which translates as “hook and prick” due to the tree possessing both straight and hooked thorns.
Like other acacia trees the umbrella thorn practices allelopathy, a process where the tree releases a chemical into the soil which prevents even its own saplings from growing and therefore reduces competition for resources.
The species name, tortilis, refers to the contorted and twisted pods and heteracantha means “different thorns” due to the umbrella thorn possessing both straight and hooked thorns.
Umbrella thorn trees are often infested by mabungu grubs, the larvae of the longhorn beetle (Cerambycidae). The grubs are high in protein and fried as a delicacy.
The gum of the umbrella thorn which is rich in carbohydrate is eaten by lesser bushbabies, vervet monkeys and baboons.