SafePlants

Allocasuarina: An Overview

Allocasuarina is a genus of trees and shrubs belonging to the flowering plant family Casuarinaceae. These plants are largely endemic to Australia, particularly the southern regions.

Considerations for Pets

• Some Allocasuarina species have long needle-like wiry branchlets with leaves reduced to whorls of small triangular teeth.

Taxonomy and Nomenclature

• Scientific Name: Allocasuarina L.A.S.Johnson, 1982
• Family: Casuarinaceae
• Kingdom: Angiosperms (Flowering plants)
• Synonyms: Casuarina species
• Type Species: A (Not fully specified in the source text)
• Common Names: Sheoak (sometimes spelled "She-oak"), Forest Oak, Rose Oak, Black Oak, Bull Oak.

Distribution and Habitat

• Primarily found in Australia, especially in the south and southeastern regions.
• Allocasuarina distyla naturally occurs in tall heath and on sandstone ridge-tops in New South Wales (NSW).
• Allocasuarina littoralis is one of the most widespread species in eastern Australia.
• Within the Wet Tropics, Allocasuarina is an adaptable genus forming a prominent component of a large number of woodland, open forest and shrubland.

Ecological Role

• Allocasuarina verticillata is a nitrogen-fixing tree, improving soil fertility.
• Glossy black cockatoos in some areas of Australia feed almost exclusively on the seeds of Allocasuarina torulosa (Forest Oak).
• Allocasuarina verticillata is known to form dense woodlands.

Morphological Characteristics and Growth Habits

• Allocasuarina species may be dioecious (having separate male and female plants) or monoecious (having both male and female flowers on the same plant).
• They can be trees or shrubs with soft wispy pendulous branchlets.
• The leaves are reduced to whorls of small triangular teeth along needle-like wiry branchlets.
• Allocasuarina verticillata has moderate growth rates and is useful as a windbreak.
• Allocasuarina crassa (Cape Pillar Sheoak) is a sprawling low shrub to small tree.
• Allocasuarina torulosa (Forest oak) is described as a graceful tree.

Species Examples

• Allocasuarina verticillata (Drooping Sheoak): A nitrogen-fixing native tree of southeastern Australia. Syn. Casuarina stricta
• Allocasuarina inophloia (Stringybark She-Oak): A shrub or small tree endemic to inland New South Wales.
• Allocasuarina littoralis (Black Sheoak): A medium-sized Australian tree.
• Allocasuarina brachystachya
• Allocasuarina crassa (Cape Pillar Sheoak): A Tasmanian endemic.
• Allocasuarina torulosa (Forest oak): A graceful tree.
• Allocasuarina luehmannii (Australian Buloke)
• Allocasuarina thalassoscopica
• Allocasuarina defungens
• Allocasuarina emuina (Emu Mountain oak)

Interactions with Other Organisms

• Ectomycorrhizal associations have been found in Allocasuarina.
• Some Pisolithus isolates formed generally well-developed ectomycorrhizas on Allocasuarina species.
• PR86 invaded the cortical cells of Allocasuarina luehmannii.
• Glossy Black-Cockatoos feed almost exclusively on the seeds of she-oaks (Allocasuarina and Casuarina).

Further Information

• Royal Botanic Gardens and Domain Trust: http://plantnet.rbgsyd.nsw.gov.au/
• Wikispecies: Allocasuarina
• Discover Life: Allocasuarina
• ARKive: Allocasuarina