''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 tall, it has green drooping branchlets up to in length. It is dioecious, that is, male and female flowers are borne on separate plants. Measuring long and 0.8–1 cm wide, the cones are perched on 0.2–1.5 cm long peduncles arising from the branchlets. The plant was discovered by Peter Brookhouse, a NPWS Ranger who worked at Sydney Harbour National Park. It was officially described by

Lawrie Johnson Lawrence Alexander Sidney Johnson Fellow of the Australian Academy of Science, FAA, (26 June 1925 – 1 August 1997) known as Lawrie Johnson, was an Australian Taxonomy (biology), taxonomic botany, botanist. He worked at the Royal Botanic Garden ...

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, consisting of the waters of Sydney Harbour, Middle Harbour, North Harbour and the Lane Cove and Parramatta Rivers, is the ria or natural harbour of Sydney, New South Wales, Australia. The harbour is an inlet of the Tasman Sea ...

.Les Robinson - Field Guide to the Native Plants of Sydney, p. 151 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 Nielsen may refer to: Business * Nielsen Gallery, an American commercial art gallery * Nielsen Holdings, global information, data, and measurement company ** Nielsen Corporation, a marketing research firm ** Nielsen Audio, formerly Arbitron, whic ...

, 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 Canopy may refer to: Plants * Canopy (biology), aboveground portion of plant community or crop (including forests) * Canopy (grape), aboveground portion of grapes Religion and ceremonies * Baldachin or canopy of state, typically placed over an ...

trees such as Port Jackson fig (''

Ficus rubiginosa ''Ficus rubiginosa'', the rusty fig or Port Jackson fig (''damun'' in the Dharug language), is a species of flowering plant native to eastern Australia in the genus ''Ficus''. Beginning as a seedling that grows on other plants ( hemiepiphyte) ...

''), smooth-barked apple ('' Angophora costata''), blueberry ash (''

Elaeocarpus reticulatus ''Elaeocarpus reticulatus'', commonly known as blueberry ash, ash quandong, blue olive berry, fairy petticoats, fringe tree, koda, lily of the valley tree and scrub ash, is species of flowering plant in the family Elaeocarpaceae, and is endemi ...

'') and cheese tree (''

Glochidion ferdinandi ''Glochidion ferdinandi'', with common names that include cheese tree (see below), is a species of small to medium–sized trees, constituting part of the plant family Phyllanthaceae. They grow naturally across eastern Australia, from south–ea ...

''). The understory consists of ''

Pittosporum revolutum ''Pittosporum revolutum'', the rough-fruited pittosporum, yellow pittosporum, Brisbane laurel or wild yellow jasmine, is a shrub that is endemic to Australia. The species grows up to 3 metres in height and has leaves that are 5 to 15 cm lo ...

'', ''

Kunzea ambigua ''Kunzea ambigua'', commonly known as white kunzea, poverty bush or tick bush, is a plant in the myrtle family, Myrtaceae and is found mainly on sandstone soils in eastern Australia. Growing up to high and wide, it bears small white flowers in ...

'' and ''

Monotoca elliptica ''Monotoca elliptica'', the tree broom heath, is a plant in the family Ericaceae, found in south-eastern Australia. Description Monotoca elliptica is a long-lived species which may grow for more than a hundred years. The plant is often seen a ...

''. The original range is unknown, as so much of the nearby bush has been cleared.

References

External links

Occurrence data for ''Allocasuarina portuensis''
from The Australasian Virtual Herbarium {{Taxonbar, from=Q4732993 portuensis Flora of New South Wales Trees of Australia Fagales of Australia Plants described in 1989 Endemic flora of Australia Dioecious plants