Allocasuarina torulosa, commonly known as forest oak, rose sheoak,[1] river oak or Baker's oak,[2] is a species of flowering plant in the family Casuarinaceae and is endemic to eastern Australia. It is a slender, usually dioecious tree that has drooping branchlets up to long, the leaves reduced to scales in whorls of four or five, and the fruiting cones long containing winged seeds (samaras) long.
Allocasuarina torulosa is slender, usually dioecious tree that typically grows to a height of . Its branchlets are drooping, up to long, the leaves reduced to erect, scale-like teeth long, arranged in whorls of four or five around the branchlets. The sections of branchlet between the leaf whorls are long, wide and more or less square in cross-section when young. Male flowers are arranged in spikes long, with 7 to 12 whorls per cm (per 0.4 in), the anthers long. Female cones are on a peduncle long, and mature cones are warty, shortly cylindrical to barrel-shaped, long and in diameter, containing brown, winged seeds (samaras) long.[3]
Forest oak was first formally described in 1789 by William Aiton, who gave it the name Casuarina torulosa in Hortus Kewensis from specimens collected by Joseph Banks.[4] [5] In 1982, Lawrie Johnson transferred the species to Allocasuarina as A. torulosa in the Journal of the Adelaide Botanic Gardens.[6] [7] Since it was the first species of the genus Allocasuarina to be named by Johnson, it is the type species of that genus.[8]
Allocasuarina torulosa grows in open forest and on rainforest fringes in moister, more nutrient rich soils than A. littoralis at altitudes from . It is widespread in north-eastern and central-eastern Queensland and on the coast and ranges of New South Wales, as far south as Macquarie Pass and Jenolan Caves. There is also an isolated population on Cape York Peninsula.
The timber is reddish pink to brown.[9] It is prized by woodworkers and woodturners as a rare and exotic timber, often used in wood turnings, knife handles and other specialist items.[10] The rose she-oak has the largest contraction along the grain (12%) of any Australian wood and needs to be dried carefully to get full value as a useful timber.[11]
The seeds of A. torulosa have been found to be a food source for the yellow-tailed black cockatoo.[12]
It grows from seed,[13] and cut or broken trees will often regenerate from the trunk.
This is a low-maintenance tree that will grow in a variety of soils and tolerate light frosts. In the USA, it is suitable for USDA hardiness zones 8–11. It may be susceptible to Armillaria and Phytophthora.[14]