Classification
The traditional circumscription of the genus Acacia is not monophyletic. This discovery has led to the breaking up of Acacia into five genera as discussed in: List of Acacia species, along with the much debated re-typification of the genus with an Australian species instead of the original African type species. That decision has lead a group of taxonomists to decide to continue to use the traditional Acacia sensu lato circumscription of the genus. This is however probably bad practice and in direct violation of modern principles of classification. When the genus is divided, the traditional acacias of Africa are now treated in the genera Vachellia and Senegalia, some of the American species are placed in Acaciella and Mariosousa, and the majority of species still treated in the genus Acacia are confined to Australia.
In common parlance, the term "acacia" is occasionally misapplied to species of the genus Robinia, which also belongs in the pea family. Robinia pseudoacacia, an American species locally known as Black Locust, is sometimes called "false acacia" in cultivation in the United Kingdom.
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