Description:

• Trees, dioecious or rarely monoecious, with persistent, at length bark-covered, woody branches from which arise numerous, very slender, ± straight, drooping, little-branched, green and usually flexible, deciduous, Equisetum-like, articulate branchlets, with several short basal articles and 1-many longer, distal articles; articles with as many 4-20 longitudinal ridges
• Leaves on branches and on branchlets reduced to small, dark, triangular scales or teeth connate at base, in a whorl of 4-20 at apex of each article (1 per longitudinal ridge); on persistent branches leaves becoming separate as stem thickens; leaf whorls, and therefore also ribs, alternating at consecutive nodes; stipules 0
• Flowers unisexual, wind-pollinated, very small and much reduced, sessile, solitary in axil of a bract and enclosed by 2 membranous lateral bracteoles, grouped into unisexual inflorescences with closely spaced alternating whorls of bracts similar to scale leaves
• Male inflorescences short to elongated catkin-like spikes, terminating deciduous branches
• Male flowers with a single stamen, enclosed in bud by 1 or 2 (anterior and posterior) concave or hood-shaped membranous perianth segments which break off at base as stamen develops; mature anther exserted, 2-thecous, basifixed
• Female inflorescences shortly stalked or subsessile, ovoid or globular heads, axillary along persistent branches
• Female flower: perianth 0; carpels 2, fused in ovary and in proximal part of style; placentation axile; ovules 2; style 2-branched, reddish, short, with 2 long, filiform, well-exserted stigmas
• Infructescences cone-like, globular, ovoid or cylindrical, ± woody, formed by enlargement and thickening of accrescent bracts and bracteoles of individual flowers, bracteoles usually more elongated and forming pairs of valves enclosing the true fruit and opening when ripe
• Fruit a small samara, very much laterally compressed, apex produced into large, ± translucent wing with 1 longitudinal nerve excurrent at apex
• Seed solitary; endosperm 0; embryo straight, often more than one
• x = 9, 11 (8, 10, 12, 13, 14)

Nomenclature:

• *Casuarinaceae
  • Brown: 571 (1814) as Casuarineae
  • Miquel: 332 (1868)
  • Bentham: 401 (1880)
  • Engler: 16 (1888) as Casuarinaceae
  • Johnson & Wilson: 237 (1993)

Distribution & Notes:

• Global: Genera 4, species 70, native to Malaysia, Australia and Polynesia; with one widespread littoral species: *Casuarina equisetifolia L. extending to Madagascar and the east coast of tropical Africa, occurring mainly in dry, infertile and saline areas; widely grown for timber and fuel wood in many parts of the tropics
• Southern Africa: Naturalised

References:

• BENTHAM, G. 1880. Casuarineae. In G. Bentham & J.D. Hooker, Genera plantarum 3. Lovell Reeve & Co., London
• BROWN, R. 1814. Casuarineae. M. Flinders, A voyage to terra australis 2. Nicol, London
• ENGLER, A. 1888. Casuarinaceae. Die natürlichen Pflanzenfamilien 3,1
• JOHNSON, L.A.S. & WILSON, K.L. 1993. Casuarinaceae. In K. Kubitzki, J.G. Rohwer & V. Bittrich, The families and genera of vascular plants - dicotyledons 2. Springer-Verlag, Berlin
• MIQUEL, F.A.W. 1868. Casuarineae. In A. de Candolle, Prodromus 16,2. Masson & Sons, Paris

Resources:

• Casuarinaceae genus: *Casuarina