Casuarina equisetifolia, commonly known as coastal she-oak, horsetail she-oak, ironwood, beach sheoak, beach casuarina, whistling tree or Australian pine is a species of flowering plant in the family Casuarinaceae and is native to the Western Pacific, Australia, New Guinea, Southeast Asia and India. It is a small to medium-sized, monoecious tree with scaly or furrowed bark on older specimens, drooping branchlets, the leaves reduced to scales in whorls of 7 or 8, the fruit 10–24 mm (0.4–0.9 in) long containing winged seeds (samaras) 6–8 mm (0.2–0.3 in) long.
Description
Casuarina equisetifolia is an evergreen tree typically growing to a height of 6–12 m (20–39 ft), sometimes to 35 m (115 ft) tall. The bark of young specimens is smooth and greyish, older trees have scaly, greyish-brown to black bark.
The foliage consists of slender, drooping branchlets up to 30 cm (12 in) long, the leaves reduced to scale-like teeth 0.3–0.5 mm (0.01–0.02 in) long, arranged in whorls of 7 or 8 (occasionally 6) around the branchlets. The sections of branchlet between the leaf whorls (the "articles") are 5–13 mm (0.2–0.5 in) long and 0.5–1.0 mm (0.02–0.04 in) wide.
This species of Casuarina is monoecious with male and female flowers produced on the same tree, unlike most other species of its same genus which are dioecious. Its male and female inflorescences are both shaped like catkins. Its male flowers appear in simple spikes 0.7–4 cm (0.28–1.57 in) long in whorls of 7 to 11.5 per cm (per 0.4 in), with anthers are 0.6–0.8 mm (0.02–0.03 in) long, whereas its female flowers are 3–13 mm (0.1–0.5 in) long on short, sparsely hairy peduncles.
The fruit is an oval woody structure 10–24 mm (0.39–0.94 in) long and 9–13 mm (0.35–0.51 in) in diameter when mature, superficially resembling a conifer cone made up of numerous...
