Vachellia is a genus of flowering plants in the legume family, Fabaceae, commonly known as thorn trees or acacias. It belongs to the subfamily Mimosoideae. Its species were considered members of genus Acacia until 2009. Vachellia can be distinguished from other acacias by its capitate inflorescences and spinescent stipules. Before discovery of the New World, Europeans in the Mediterranean region were familiar with several species of Vachellia, which they knew as sources of medicine, and had names for them that they inherited from the Greeks and Romans. The wide-ranging genus occurs in a variety of open, tropical to subtropical habitats, and is locally dominant. In parts of Africa, Vachellia species are shaped progressively by grazing animals of increasing size and height, such as gazelle, gerenuk and giraffe. The genus in Africa has thus developed thorns in defence against such herbivory. The members of Vachellia are trees or shrubs, sometimes climbing, and are always armed. Of the 163 species currently assigned to Vachellia, 52 are native to the Americas, 83 to Africa, Madagascar and the Mascarene Islands, 32 to Asia and 9 to Australia and the Pacific Islands.

Vachellia gerrardii is a slender single-stemmed shrub or small tree growing 5 to 10 meters tall. It is usually found growing in woodland and wooded grasslands. It is not picky about its soil, enjoying all soil types, and actually prefers brackish or clay soils. It has variable bark; some trees may have rough bark while others, even within the same population, may have will have smooth bark. However, the younger branches will always be reddish in colour. This tree will grow in most gardens, and is an attractive addition to the indigenous garden. It grows well from seed, has some resistance to frost and is drought resistant.