Allocasuarina fibrosa, commonly known as woolly sheoak, is a species of flowering plant in the family Casuarinaceae and is endemic to the south-west of Western Australia. It is a dioecious shrub that has branchlets long, the leaves reduced to scales in whorls of four, and the mature fruiting cones long containing winged seeds (samaras) long.
Allocasuarina fibrosa is a dioecious shrub that typically grows to a height of . Its branchlets are long, the leaves reduced to erect, scale-like teeth long, arranged in whorls of four around the branchlets. The sections of branchlet between the leaf whorls (the "articles") are long. Male flowers are arranged in spikes long, the anthers long. Female cones are more or less cylindrical to spherical and covered with hairs, mature cones long and in diameter, often with awn-like projections up to long. The samaras brown to black and long. Flowering occurs in July and August. This sheoak is similar to Allocasuarina grevilleoides.[1] [2]
This species was first formally described in 1928 by Charles Gardner who gave it the name Casuarina fibrosa in the Journal of the Royal Society of Western Australia, from specimens he collected near Tammin in 1926.[3] It was reclassified in 1982 as Allocasuarina fibrosa by Lawrie Johnson in the Journal of the Adelaide Botanic Gardens.[4] The specific epithet (fibrosa) refers to the long fibres on the cones.[5]
Woolly sheoak grows in tall, open heath in sandy soil over laterite and is only known from several populations near Tammin and Quairading in the Avon Wheatbelt bioregion of south-western Western Australia.[6]
Allocasuarina fibrosa is listed as "vulnerable" under the Australian Government Environment Protection and Biodiversity Conservation Act 1999 and as "Threatened" by the Western Australian Government Department of Biodiversity, Conservation and Attractions, meaning that it is in danger of extinction.[7]