Among Bursera and Berkheya, which can be found in South Africa?
Bursera:  They are native (often for many species endemic) to the Americas, from the southern United States south through to northern Argentina, in tropical and warm temperate forest habitats. Berkheya: Berkheya is a genus of flowering plants in the aster family, Asteraceae, and the subfamily Carduoideae, the thistles. Berkheya:  Of about 75 species, 71 can be found in South Africa.
Berkheya