Young persistent branchlets distinguished from deciduous branchlets by shorter segments and differences in shape or size of leaves; furrows deep and closed, concealing stomates. Infructescences pedunculate, pubescent at least when immature; bracts thin in exposed portion, not vertically expanded; bracteoles ± protruding from surface of infructescence, never greatly thickened, always lacking dorsal protuberance. Samaras pale yellow-brown or grayish, dull, glabrous. x = 9.
Almost throughout range of family.
Species 17 (3 in the flora).
Hybrids are frequent in cultivation; in the flora, hybrids are known between all combinations of the three species.
|1||Longitudinal ridges of branchlets flat or slightly rounded-convex; leaf teeth 12–17; teeth on young permanent shoots long-recurved.||Casuarina glauca|
|1||Longitudinal ridges of branchlets prominently angular; leaf teeth (6–)7–10; teeth on young permanent shoots erect to spreading.||> 2|
|2||Branchlets ± densely and obviously pubescent; teeth (6–)7–8, not marcescent; infructescence body 12–24 × 9–11 mm, bracteoles acute; samaras 6–8mm.||Casuarina equisetifolia subsp. equisetifolia|
|2||Branchlets sparsely and minutely pubescent; teeth 8–10, marcescent; infructescence body 7–14 × 4–6 mm, bracteoles broad-acute; samaras 3–4 mm.||Casuarina cunninghamiana subsp. cunninghamiana|