Casuarina

Linnaeus
Amoen. Acad. 4: 143. 1759.
Common names: She-oak
Etymology: Neo-Latin casuarius, cassowary, from resemblance of drooping branchlets to feathers of the cassowary
Treatment appears in FNA Volume 3.

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.

Distribution

Almost throughout range of family.

Discussion

Species 17 (3 in the flora).

Hybrids are frequent in cultivation; in the flora, hybrids are known between all combinations of the three species.

Selected References

None.

Key

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