Flora of the Hawaiian Islands
Dicotyledon Literature for Casuarina equisetifolia
Wagner et al., 1990, 1999; Lorence & Wagner, 2020.
   Casuarinaceae -- The She-oak Family Bibliography
      Casuarina equisetifolia

Common name(s): Australian pine, beefwood, she-oak, common ironwood, paina
General Information
DistributionNative to Australia, widely cultivated throughout tropical and subtropical regions, naturalized in many of these areas.In the Hawaiian Islands, naturalized on Kure, Midway, Pearl and Hermes, Lisianski, Laysan, French Frigate Shoals, Ni`ihau, Kaua`i, O`ahu, Moloka`i, Lana`i, Maui, Kaho`olawe, Hawai`i.

Tree to 20 m tall; branches long, slender, tips drooping, pubescent, branchlets cylindrical, 1‒1.5 mm in diameter, jointed, internodes 6‒8 mm long with 6‒8 prominent ridges.
Nodal leaf-sheaths with (6)7(‒9)teeth, pale green, united at base into a short tube, free part 0.5‒1.0 mm long, 0.3‒0.5 mm wide, glabrous, but margin shortly ciliate.
Staminate inflorescences in densely flowered spikes, 1‒6 cm long; bracts densely pubescent; pistillate inflorescences in scattered or clustered ovoid-subglobose heads, 4‒8 mm long, stalk 2‒12 mm long; bracts ± similar to those of staminate inflorescence, perianth 0, pistil bicarpellary, ovary unilocular, stigmas 2‒3 mm long, exserted, red.
Fruit subglobose to elongate and oblong-globose, 1.2‒2.2 cm long, ca. 1.1‒1.4 cm in diameter, valves broadly ovate, protruding ca. 2 mm, pubescent, apex obtuse.
Seeds 6‒7 mm long including wing.
2n = 18.
David Lorence & W. L. Wagner