Plants trees and shrubs, the species dioecious or monoecious; woody branches producing slender, green, often drooping, Equisetum-like and deciduous assimilatory branchlets with longitudinally grooved inteed, Leaves without stipules. small, scale-like, whorled and more or less united to form a toothed sheath at each node. Inflorescences with shorls of bracts, each subtending 2 bracteoles and a sessile flower. male inflorescences at tips of deciduous branchlets, spicate; female inflorescences globose to ovoid heads on short side branches. Flowers small, inconspicuous; male flowers with -2 deciduous tepals and 1 stamen, anthers exserted at anthesis; female flowers without a perianth; ovaries 1-celled; styles short, with e long, slender stigmas exserted at anthesis. Infrutescences cone-like, with woody bracts and bracteoles, the latter forming a pair of valves enclosing the fruits. Fruits 1-seeded, compressed, the upper part extended into a translucent wing.
The Casuarinaceae family includes 4 genera. They are native to Australia, southeast Asia, and islands of the Pacific. The roots often have nodules with nitrogen-fixing bacteria.
Only one genus, Casuarina, and one species, Casuarinaequistifola is known to be present in Somaliland and Somlaia. It is grown as an ornamental.