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 reficiens, previously known as Acacia reficiens, is a small deciduous tree or shrub often growing in an upside-down cone shape and with a relatively flat crown. It can grow up to 5 metres in height. In Namibia’s Kaokoveld region, the branches of this tree are used for fencing and the bark is used to curdle milk, while the thorns can be used to pierce ears. Medicinally root extracts are used as a cure against stomach-complaints and as an aid during childbirth. The seeds can be baked in hot ash, crushed, ground and mixed with tobacco to use as snuff. This species also makes an attractive bonsai specimen.