Casuarina is a genus of 17 tree species in the family Casuarinaceae, native to Australia, the Indian subcontinent, southeast Asia, and islands of the western Pacific Ocean. It was once treated as the sole genus in the family, but has been split into three Australian genera and a fourth.  They are evergreen shrubs and trees growing to 35 m (115 ft) tall. The slender, green to grey-green twigs bearing minute scale-leaves in whorls of 5–20. The apetalous flowers are produced in small catkin-like clusters (Wikiepdia).