Acacia ( or ) is a monophyletic genus of flowering plants in the legume family, Fabaceae, commonly known as thorn trees or shittah trees. The genus name is derived via Latin from ancient Greek  . It was the name used by Theophrastus and Dioscorides to denote thorn trees, the word root being or , meaning "thorn" and "point" respectively. Before discovery of the New World, Europeans in the Mediterranean region were familiar with several species of Acacia, which they knew as sources of medicine, and had names for them that they inherited from the Greeks and Romans.