Sentence:  Virtually all the trees in the home range of the baboons are acacias of just two species: the fever tree, "Acacia xanthophloea" (18.4% of feeding bouts), and, on somewhat higher, drier ground, the <WSD>umbrella tree</WSD>, "A. tortilis" (5.0%). 
Meaning of the word marked with <WSD> tags:  (species), the (umbrella thorn).