Allocasuarina portuensis
Nielsen Park she oak | |
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In the Australian National Botanic Gardens | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Rosids |
Order: | Fagales |
Family: | Casuarinaceae |
Genus: | Allocasuarina |
Species: | A. portuensis
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Binomial name | |
Allocasuarina portuensis |
Allocasuarina portuensis, commonly known as Nielsen Park she-oak, of seven or eight, the fruiting cones 12–15 mm (0.47–0.59 in) long containing winged seeds 4–5 mm (0.16–0.20 in) long.
Description
Allocasuarina portuensis is a slender, dioecious shrub that typically grows to a height of 3–5 m (9.8–16.4 ft) and has smooth bark. Its branchlets are spreading to drooping, up to 270 mm (11 in) long, the leaves reduced to erect or slightly overlapping, spreading to curved backwards, scale-like teeth 0.7–1.1 mm (0.028–0.043 in) long, arranged in whorls of seven or eight around the branchlets. The sections of branchlet between the leaf whorls are 13–20 mm (0.51–0.79 in) long and 0.8–1 mm (0.031–0.039 in) wide, usually with a faint, waxy bloom. Male flowers are arranged in spikes resembling a string of beads 50–100 mm (2.0–3.9 in) long, with about 3.5 to 4.5 whorls per centimetre (per 0.39 in.), the anthers 0.8–1 mm (0.031–0.039 in) long. Female cones are borne on a peduncle 2–15 mm (0.079–0.591 in) long, the mature cones 12–15 mm (0.47–0.59 in) long and 8–10 mm (0.31–0.39 in) in diameter, the winged seeds dark brown and 4–5 mm (0.16–0.20 in) long.[2][3][4][5][6]
Nielsen Park she-oak resembles Allocasuarina rigida and A. diminuta, but both usually lack male flowers arranged like a string of beads. Allocasuarina littoralis occurs in the same area as A. portuensis but is a tree with fissured bark and also lacks the unusual flower arrangement of male flowers.[6]
Taxonomy
Allocasuarina portuensis was first formally described in 1989 by Lawrie Johnson in Flora of Australia from specimens collected in Sydney Harbour National Park in 1986. The species was discovered by Peter Brookhouse in the south-eastern part of Nielsen Park earlier the same year.[5][6][7] The specific epithet, (portuensis) means "inhabiting a port".[8]
Distribution and habitat
At the time of its discovery, only two male and six female plants were known, at six locations in the south-eastern part of Nielsen Park. It is likely that the species previously had a wider distribution, since the vegetation of Neisen Park at the time of European settlement was widespread on the foreshore of
Conservation
Allocasuarina portuensis is listed as "endangered" under the Australian Government Environment Protection and Biodiversity Conservation Act 1999 and the New South Wales Government Biodiversity Conservation Act 2016.[2][3][6]
Efforts to propagate and reintroduce the species began from the time it was identified, and plants were planted at several locations around Nielsen Park and nearby Gap Bluff and Hermit Point. 54 of these remained alive in 2000.[6]
References
- ^ "Allocasuarina portuensis". Australian Plant Census. Retrieved 3 August 2023.
- ^ a b c "Nielsen Park She-oak - profile". New South Wales Government Office of Environment and Heritage. Retrieved 3 August 2023.
- ^ a b Wilson, Karen L.; Johnson, Lawrence A.S. "Allocasuarina portuensis". Royal Botanic Garden Sydney. Retrieved 3 August 2023.
- ^ "Allocasuarina portuensis". Australian Biological Resources Study, Department of Agriculture, Water and the Environment: Canberra. Retrieved 3 August 2023.
- ^ a b Wilson, Karen L.; Johnson, Lawrence A.S. (1989). George, Alex S. (ed.). Flora of Australia (PDF). Vol. 3. Canberra: Australian Government Publishing Service. p. 152. Retrieved 3 August 2023.
- ^ a b c d e f Matthes, Maria; Nash, Sharon. "Allocasuarina portuensis Recovery Plan" (PDF). Australian Government Department of Climate Change, Energy, the Environment and Water. Retrieved 3 August 2023.
- ^ "Allocasuarina portuensis". APNI. Retrieved 3 August 2023.
- ISBN 978-0-7318-1211-0p. 151