A densely foliaged small to medium tree. The foliage, like other Allocasuarina species, is made up of fine green branchlets with the leaves reduced to tiny scales.
The bark is finely furrowed and grey.
On male trees, an attractive feature is the flowers which consist of numerous rusty-brown anthers that coat the outer branchlets for several centimetres.
Female flowers are tiny, inconspicuous bundles of red silky stigmas, usually scattered on older branches. If fertilisation is succesful, these mature into solid, woody cones, a little larger than those of the Drooping Sheoke, .
Young trees of this species closely resemble the River Sheoke, Casuarina cunninghamii in the texture of the foliage and bark. Unfortunately, this confusion has on occasion been extended to collectors of seed for indigenous nurseries. After approximately five yearsa, the extreme vigour and large size of the River Sheoke becomes apparent. The River Oak also begins to produce marble-sized cones about this time. The valves of these cones are able to be crushed between the finger-tips. Removal of River Sheokes is difficult due to the vigorous suckering ability of this species which is native to NSW and Queensland.