Sydney Plains Greenhood - profile

Indicative distribution

Loading map...

Key:

known

predicted

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: Pterostylis saxicola

Conservation status in NSW: Endangered

Commonwealth status: Endangered

Gazetted date: 31 Oct 1997

Profile last updated: 14 Oct 2024

Description

A ground orchid with reddish brown and green translucent flowers on a slender stem to 35 cm tall. Plants have 5 - 8 rosette leaves (to 2.5 cm x 1.1 cm), and 2 - 4 closely sheathing stem leaves. Was previously regarded as a form of Pterostylis gibbosa but is now recognised as a distinct taxon. Features that distinguish it from P. gibbosa include: transparent flowers with a dark red-brown shiny lateral sepal; decurved lateral sepals with incurved free points; and broad obovate, dark red-brown labellum (middle petal) which is broadly grooved centrally and with a very large basal lobe.

Distribution

Restricted to western Sydney between Freemans Reach in the north and Picton in the south. There are very few known populations and they are all very small and isolated. Two populations occur within a conservation reserve (Georges River National Park; Scheyville NP).

Habitat and ecology

Occurs primarily on the Cumberland Plain along an ecological gradient from clay soils derived from Ashfield Shale to thin accumulations of humus rich sandy soils on Hawkesbury Sandstone sheets and rock shelves. Habitat ranges from grassy woodland on flat to gently sloping landscapes on shale soils, to open-forest on hilly landscapes on transitional soils, and woodland on the rims and steep sides of river valleys on sandstone soils. The species has also been recorded outside the Cumberland Plain in grassy woodland on Devonian slate.
All species of Pterostylis are deciduous and die back to fleshy, rounded underground tuberoids. Rosettes start to emerge around March/April for this species, with flowering from late September to November. Flowering time and abundance may vary due to climatic conditions. The above ground parts of the plant wither and die following seed dispersal and the plant persists as a tuberoid until the next year.
Typically occurs as scattered individuals or in small groups.

Regional distribution and habitat

Click on a region below to view detailed distribution, habitat and vegetation information.

Threats

Habitat loss due to clearing for development.
Grazing.
Unauthorised collection.
Weed invasion.
Inappropriate fire regimes.
Given extremely small population size and restricted distribution, susceptible to local extinction due to environmental and demographic stochasticity and catastrophic events.
Local residents dumping rubbish / garden waste in or near areas where the species occurs.
Areas where the species occurs have been slashed or maintained.
Trampling from general activity of school students walking through the site.
Unauthorised access; trail bike riding creating surplus of trails and tracks
Lack of distributional information to ensure protection and best practice management.
Need to understand the viability of seed and the relationship with symbiotic fungi. Need to collect seed from all known populations for storage at Mt Annan Botanical Gardens.

Recovery strategies

Priority actions are the specific, practical things that must be done to recover a threatened species, population or ecological community. The Office of Environment and Heritage has identified 27 priority actions to help recover the Sydney Plains Greenhood in New South Wales.

Activities to assist this species

Where developments or activities are planned in potential habitat, targeted survey should be conducted at an appropriate time of year and appropriate protection measures should be implemented if the species is present.
Introduce measures to prevent habitat degradation related to unrestricted access to habitat.
Undertake appropriate weed control activities when necessary.
Protect known habitat areas from clearing and disturbance.
Effective management of this species will require greater understanding of the role of fire in population persistence.
Survey and monitor known populations to gain greater insight into the current status of the species.

Information sources

Fairley, A. and Moore, P. (2000) Native plants of the Sydney district: an identification guide. 2nd Edition. (Kangaroo Press, East Roseville)

IBRA Bioregion	IBRA Subregion	Known or predicted	Geographic restrictions region

South Eastern Highlands	Kanangra	Known	None
Sydney Basin	Burragorang	Predicted	None
Sydney Basin	Cumberland	Known	None
Sydney Basin	Sydney Cataract	Known	None

Images

Flower detail of Sydney Plains greenhood. <a href="http://picasaweb.google.com/orkology" class="linkBlack100" target="_blank">Greg Steenbeeke, Orkology</a>

Flower detail of Sydney Plains greenhood. Greg Steenbeeke, Orkology Image 1 of 5.
View slideshow.

Related information

Get involved

Report a sighting

Nature conservation

Threatened species