The
Casuarinaceae are a
family of
dicotyledonous flowering plants placed in the order
Fagales, consisting of four
genera and about 70 species of trees and shrubs native to the
Australia,
Southeast Asia,
Malesia,
Papuasia, and the
Pacific Islands. At one time, all species were placed in the genus
Casuarina.
Lawrie A. S. Johnson separated out many of those species and renamed them into the new genera of
Gymnostoma in 1980 and 1982,
Allocasuarina in 1982, and
Ceuthostoma in 1988, with some additional formal descriptions of new species in each other genus. At the time, it was somewhat controversial. The
monophyly of these genera was later supported in a 2003 genetics study of the family. In the
Wettstein system, this family was the only one placed in the order Verticillatae. Likewise, in the
Engler,
Cronquist, and
Kubitzki systems, the Casuarinaceae were the only family placed in the order Casuarinales.