Vachellia robusta

Broadpod robust thorn
Enkeldoring
Mooka
Mvumbangwenya
Umngamanzi

This species was formerly included in the genus Acacia, but has since been moved to the genus Vachellia.

This is a medium-sized, upright, deciduous thorn tree reaching up to 10 m. The narrow upright growth and majestic stature, makes it one of the most popular thorn trees in southern Africa. Vachellia robusta occurs in a diverse range of habitats, in southern Africa it is very common in the warm dry savannas and is resistant to drought and frost. It is distributed from tropical Africa southwards to Namibia, Mozambique, Swaziland and South Africa. Vachellia robusta is commonly found in open forests and woodlands, often near streams. The main stem is grey to blackish with rough hairy branches. The white thorns are straight and paired. The heartwood is pinkish brown to reddish brown and distinctly demarcated from the wide whitish sapwood. The wood is brittle and moderately durable and rarely used for furniture.

Flowers are creamy white pompons appear together with or after the new leaves in spring, followed by the dehiscent greyish brown, straight and broad, seed pods adorning the tree.
The leaves are browsed by mammals, the strongly scented flowers attract bees and butterflies, and many other insects. Small birds like to build their nests in the densely thorny branches, as the thorns offer excellent protection from predators.

This tree has many medicinal uses. The powdered root is applied to swellings, and the roots have been used to treat dysmenorrhea, infertility in women and bilharzia. The stem bark is used to treat gonorrhea, abdominal pain and skin conditions. The leaves are used to treat snake bites.

Vachellia robusta is modulated by nitrogen-fixing Rhizobium soil bacteria, which fix atmospheric nitrogen (N2) and convert it to ammonia (NH4+) - a form of nitrogen usable by plants. The bacteria benefit by having access to organic compounds that the plant produces through photosynthesis.