Sydney Plains Greenhood - profile

Scientific name: Pterostylis saxicola
Conservation status in NSW: Endangered
National conservation status: Endangered

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.

Location and habitat

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. Only one population occurs within a conservation reserve (Georges River National Park).

Habitat and ecology

Most commonly found growing in small pockets of shallow soil in depressions on sandstone rock shelves above cliff lines. The vegetation communities above the shelves where Pterostylis saxicola occurs are sclerophyll forest or woodland on shale/sandstone transition soils or shale soils.
All species of Pterostylis are deciduous and die back to fleshy, rounded underground tuberoids. The time of emergence and withering has not been recorded for this species, however flowering occurs from October to December and may vary due to climatic conditions. The above ground parts of the plant whither 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 information
This species is found in the following catchment management authority regions. Click on a region name to see more details about the distribution, vegetation types and habitat preference of the species in that region.

Threats

Habitat loss due to clearing for development.
Habitat degradation related to unrestricted access and 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.

Recovery strategies

Priority actions are the specific, practical things that must be done to recover a threatened species, population or ecological community. The Department of Environment and Conservation has identified 14 priority actions to help recover the Sydney Plains Greenhood in New South Wales.

What needs to be done to recover 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.
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.

References

Fairley, A. and Moore, P. (2000). Native plants of the Sydney district: an identification guide. 2nd edn. Kangaroo Press, East Roseville.
NSW Scientific Committee (1997) Pterostylis saxicola (an orchid) - Endangered species determination - final. DEC (NSW), Sydney.