Allocasuarina, commonly known as sheoak[4] or she-oak,[5] is a genus of flowering plants in the family Casuarinaceae and is endemic to Australia.

Plants in the genus Allocasuarina are trees or shrubs with soft, pendulous, green branchlets, the leaves reduced to scale-like teeth.

Female flowers are in spikes on short side-branches, the female spikes later developing into cone-like structures enclosing winged seeds known as samaras, which are reddish-brown to black, with thickly woody bracteoles that extend only slightly beyond the cone body.

[3][4][5][6][7][8][9] The genera Allocasuarina was created out of a grouping of plants formerly placed in Casuarina, because of subtle but consistent differences – Casuarina species have 6 to 20 scale-like teeth in each whorl of leaves, their samaras are grey or yellowish-brown, and the bracteoles of the fruiting cones are thin, woody and extend well beyond the cone body.

[9] The genus Allocasuarina was first formally described in 1982 by Lawrence Johnson in the Journal of the Adelaide Botanic Gardens.