Allocasuarina portuensis
Encyclopedia
Allocasuarina portuensis, commonly known as the Nielsen Park She-Oak, is an extremely rare plant growing in Sydney
, Australia
. Encountered as a shrub or small slender tree, up to 5 metres (16 ft) tall, it has green drooping branchlets up to 27 cm (11 in) in length. It is dioecious
, that is, male and female flowers are borne on separate plants. Measuring 1.2–1.5 cm (0.5-0.6 in) long and 0.8–1 cm wide, the cones are perched on 0.2–1.5 cm long peduncles arising from the branchlets.
It was officially described by Lawrie Johnson
in 1989. The specific epithet portuensis is from the Latin, meaning “inhabiting a port”, as this species was originally found at Port Jackson
. It most resembles Allocasuarina rigida and A. distyla
and can be distinguished by differences in the male flowers. A. portuensis was originally identified in 1986 from ten specimens at Nielsen Park
, in the city's eastern suburbs. Those original plants have now died. However, 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.
The original habitat was forest over sandstone-based soils, with canopy trees such as Port Jackson fig (Ficus rubiginosa), smooth-barked apple (Angophora costata
), blueberry ash (Elaeocarpus reticulatus
) and cheese tree (Glochidion ferdinandi
). The understory consists of Pittosporum revolutum
, Kunzea ambigua
and Monotoca elliptica
. The original range is unknown, as so much of the nearby bush has been cleared.
Sydney
Sydney is the most populous city in Australia and the state capital of New South Wales. Sydney is located on Australia's south-east coast of the Tasman Sea. As of June 2010, the greater metropolitan area had an approximate population of 4.6 million people...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
. Encountered as a shrub or small slender tree, up to 5 metres (16 ft) tall, it has green drooping branchlets up to 27 cm (11 in) in length. It is dioecious
Dioecious
Dioecy is the property of a group of biological organisms that have males and females, but not members that have organs of both sexes at the same time. I.e., those whose individual members can usually produce only one type of gamete; each individual organism is thus distinctly female or male...
, that is, male and female flowers are borne on separate plants. Measuring 1.2–1.5 cm (0.5-0.6 in) long and 0.8–1 cm wide, the cones are perched on 0.2–1.5 cm long peduncles arising from the branchlets.
It was officially described by Lawrie Johnson
Lawrence Alexander Sidney Johnson
Lawrence Alexander Sidney Johnson, known as Lawrie Johnson, was an Australian taxonomic botanist. He worked at the Royal Botanic Gardens, Sydney, for the whole of his professional career, as a botanist , Director and Honorary Research Associate .Alone or in collaboration with colleagues, he...
in 1989. The specific epithet portuensis is from the Latin, meaning “inhabiting a port”, as this species was originally found at Port Jackson
Port Jackson
Port Jackson, containing Sydney Harbour, is the natural harbour of Sydney, Australia. It is known for its beauty, and in particular, as the location of the Sydney Opera House and Sydney Harbour Bridge...
. It most resembles Allocasuarina rigida and A. distyla
Allocasuarina distyla
Allocasuarina distyla, or Scrub She-Oak, is a shrub or small tree of the She-oak family Casuarinaceae endemic to New South Wales....
and can be distinguished by differences in the male flowers. A. portuensis was originally identified in 1986 from ten specimens at Nielsen Park
Nielsen Park
Nielsen Park is a part of Sydney Harbour National Park at the suburb of Vaucluse in the eastern suburbs of Sydney, Australia. It is a popular recreation area and beach on Port Jackson. The kiosk is dated from 1914....
, in the city's eastern suburbs. Those original plants have now died. However, 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.
The original habitat was forest over sandstone-based soils, with canopy trees such as Port Jackson fig (Ficus rubiginosa), smooth-barked apple (Angophora costata
Angophora costata
Angophora costata is a common woodland and forest tree of Eastern Australia and is known by a variety of names including smooth-barked apple, rose gum, rose apple or Sydney red gum. It grows primarily on sandstone soils, usually on headlands, plateaus or other elevated areas. A...
), blueberry ash (Elaeocarpus reticulatus
Elaeocarpus reticulatus
Elaeocarpus reticulatus, the Blueberry Ash, is a large shrub or tree which can grow to a height of 15m. In NSW rainforests it can attain a height of 30 metres. Its most conspicuous features are white or pink cup-shaped flowers with fringed edges and round blue fruits. Strictly botanically, the...
) and cheese tree (Glochidion ferdinandi
Glochidion ferdinandi
Glochidion ferdinandi, commonly known as the cheese tree, is a species of tree in the Phyllanthaceae family. It is native to eastern Australia, where it grows in rainforests and wetter sclerophyll forests...
). The understory consists of Pittosporum revolutum
Pittosporum revolutum
Pittosporum revolutum is a shrub that is endemic to Australia....
, Kunzea ambigua
Kunzea ambigua
Kunzea ambigua, commonly known as the White Kunzea, Poverty Bush or Tick Bush, is a common shrub of the myrtaceae family found on sandstone soils in eastern Australia. Growing up to high and wide, it bears small white flowers in spring. Used in native gardening, it attracts native insects...
and Monotoca elliptica
Monotoca elliptica
Monotoca elliptica, known as the Tree Broom Heath is a plant in the heath family, found in south-eastern Australia. A long lived species which may grow for more than a hundred years....
. The original range is unknown, as so much of the nearby bush has been cleared.