Nature conservation

Threatened species

Nielsen Park She-oak - profile

Indicative distribution

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The areas shown in pink and/purple are the sub-regions where the species or community is known or predicted to occur. They may not occur thoughout the sub-region but may be restricted to certain areas. ( click here to see geographic restrictions). The information presented in this map is only indicative and may contain errors and omissions.
Scientific name: Allocasuarina portuensis
Conservation status in NSW: Endangered
Commonwealth status: Endangered
Profile last updated: 24 Jul 2019


A slender shrub, 3 - 5 m high with branchlets drooping to spreading and dark green in colour. It is a dioecious species (male and female flowers on different plants). Branchlet articles are cylindrical, usually with a faint waxy bloom, hairless, 13 - 20 mm long and 0.8 - 1.0 mm in diameter. Teeth on articles are seven or eight per whorl, spreading to recurved, 0.7 - 1.1 mm long. Cones are cylindrical and borne on peduncles 2 - 15 mm long.


The original known habitat of the Neilsen Park She-oak is at Nielsen Park, in Woollahra local government area. There are no plants left at the original site where it was discovered. However, propagation material has been planted successfully at a number of locations at Nielsen Park and other locations in the local area, e.g. Gap Bluff, Hermit Point and Vaucluse House.

Habitat and ecology

  • The original habitat is tall closed woodland. Canopy species include: Ficus rubiginosa, Angophora costata, Elaeocarpus reticulatus and Gloichidion ferdinandi with a shrub layer of Pittosporum revolutum, Kunzea ambigua and Monotoca elliptica.
  • The original habitat occurs above a sandstone shelf approximately 20 m above the harbour. The shallow sandy soils are highly siliceous, coarsely textured and devoid of a soil profile. The plantings have occurred on similar soils.
  • Flowering occurs throughout the winter months (April-August), though many of the in situ plantings have also been observed to flower during January and March. The species is probably wind pollinated.
  • Species in the Casuarinaceae are generally obligate seed regenerators. Most species are killed by fire, although some species can resprout. It is most conservative to assume that it is killed by fire unless otherwise shown.
  • Reproductive success is dependent on the availability of pollen.
  • Life span is greater than 10 years, and possibly up to 30 years.

Regional distribution and habitat

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Recovery strategies

Activities to assist this species

Information sources

IBRA Bioregion IBRA Subregion Known or predicted Geographic restrictions region
OceanHawkesbury Shelf Known None
Sydney BasinPittwater Known East of Gladesville bridge, within 5 km of Sydney Harbour foreshore