Locally known as Mthethe, it is also known as White Thorn.
From the Useful Tropical Plants Database
It is a fast-growing, deciduous tree growing about 10 – 25 metres tall. The tree has short, hooked thorns (prickles), usually less than 1cm long.
The tree is harvested from the wild as a lesser important but still commercial source of gum, which is edible. It is also used locally as a medicine and source of materials, whilst it also has a good reputation for repelling snakes and crocodiles. The plant is grown as a hedge and also for improving soil fertility.
A good summary of the tree can be seen in a video by Gus Le Breton the African Plant Hunter