Casuarina - The generic name is derived from the Malay word for cassowary, kasuari, an allusion to the similarity between the feathers of that bird and the foliage of plants of the genus Casuarina. Despite this origin, the tree is called rhu in current Malay, its common name in that language.
The genus includes 17 species of the family Casuarinaceae, native to Australasia, the Indian subcontinent, Southeast Asia and the islands of the Western Pacific. The genus was considered the only one in the family Casuarinaceae, which would therefore be monotypic, but recent studies have led to the division of that family into three distinct genera (see Casuarinaceae). The species of the genus Casuarina are evergreen shrubs and trees, with some tree species reaching up to 35 m in height. They are characterized by their slender trunks, slightly decumbent branching and a grayish, rough and not very thick rhytidome.