Species Profile and Threats Database

For information to assist proponents in referral, environmental assessments and compliance issues, refer to the Policy Statements and Guidelines (where available), the Conservation Advice (where available) or the Listing Advice (where available).
In addition, proponents and land managers should refer to the Recovery Plan (where available) or the Conservation Advice (where available) for recovery, mitigation and conservation information.

EPBC Act Listing Status Listed as Endangered as Genoplesium rhyoliticum
Recovery Plan Decision Recovery Plan required, included on the Commenced List (1/11/2009).
Adopted/Made Recovery Plans
Policy Statements and Guidelines Draft survey guidelines for Australia's threatened orchids (Department of the Environment, 2013b) [Admin Guideline].
Federal Register of
    Legislative Instruments
Declaration under s178, s181, and s183 of the Environment Protection and Biodiversity Conservation Act 1999 - List of threatened species, List of threatened ecological communities and List of threatening processes (Commonwealth of Australia, 2000) [Legislative Instrument] as Genoplesium rhyoliticum.
State Listing Status
NSW: Listed as Endangered (Threatened Species Conservation Act 1995 (New South Wales): December 2013) as Genoplesium rhyoliticum
Scientific name Genoplesium rhyoliticum [55116]
Family Orchidaceae:Orchidales:Liliopsida:Magnoliophyta:Plantae
Species author D.L.Jones
Infraspecies author  
Reference Jones, D.L. (1991) Austral. Orchid Res. 2: 70
Other names Corunastylis rhyolitica [78697]
Distribution map Species Distribution Map

This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.

Illustrations Google Images
Line drawing in Jones (1991) Aust. Orchid Res 2; Bishop (1996), Field Guide to Orchids Plate 141.

The Pambula Midge-orchid is a terrestrial tuberous herb, growing to 19 cm tall (Jones 1991b).

This species is restricted to several rock outcrops near Pambula on the south coast of NSW and was first collected in 1985 (NSW NPWS 2003b). Previously known only from the type locality on Old Hut Creek, five other colonies have been discovered since then (Jones 1991b; NSW NPWS 2003b). The species is confined to an area of 70 km². Three of the colonies are conserved in the South East Forests NP (NSW NPWS 2003b).

A morphological examination of the Genoplesium group showed that Genoplesium is monotypic (represented by a single species) and that Corunastylis should be recognised for the majority of species in the group (Jones et al. 2002).

Corunastylis rhyolitica (previously Genoplesium rhyoliticum) is closely related to G. morrisii but has smaller flowers, an obovate labellum with a narrow, tapered callus extending the full length of the lamina and lacks any marginal cilia on the petals (Jones 1991b).

This species occurs in steeply dissected country on very shallow soils associated with outcrops of rhyolite (Bishop 1996; Jones 1991b; NSW NPWS 2003b).

These sites are often too drought-stressed to support shrubs or trees. Vegetation is dominated by a dense cover of small fruticose lichens in some locations, and by lichens and/or moss in others. Other geophytes, notably orchids such as Pterostylis parviflora, Thelymitra spp., Calochilus spp. and Calaena spp., and other herbs including Drosera peltata ssp. auriculata and Thysanotus tuberosus are common associates (NSW NPWS 2003b). At one site, the orchid grows in dense shrubby heathland where the main species are Kunzea ambigua, Calytrix tetragona, Platysace lanceolata, Melaleuca armillaris, Epacris cf. microphylla, Leionema ralstonii and Pseudanthus divaricatus (NSW NPWS 2003b).

This species is a long-lived tuberous geophyte which has a relatively brief period of activity usually in late spring to early summer and is stimulated by rain. Growth is very rapid with flowering and fruiting taking only 3-4 weeks. Flowers have been observed from Dec. to late Jan. (Jones 1991b; S. Clark in NSW NPWS 2003b ). The tubers are large (about 1.8 cm in diameter), are buried only 2-6 cm deep and account for most of the biomass in flowering specimens (NSW NPWS 2003b).

This orchid is an outcrossing species (D.L.Jones 2001, pers. comm.) which is probably pollinated by small flies, and fruits well. Seed dispersal is passive with minute dust-like seeds potentially capable of being dispersed considerable distances (NSW NPWS 2003b).

Seedlings do not reach reproductive maturity until at least their third year. Like all orchids, Corunastylis has an obligatory requirement for a mycorrhizal fungus which extends throughout the life of the plant (NSW NPWS 2003b).

The following table lists known and perceived threats to this species. Threats are based on the International Union for Conservation of Nature and Natural Resources (IUCN) threat classification version 1.1.

Threat Class Threatening Species References
Invasive and Other Problematic Species and Genes:Invasive Non-Native/Alien Species:Vegetation and habitat loss caused by dieback Phytophthora cinnamomi Threat abatement plan for disease in natural ecosystems caused by Phytophthora cinnamomi (Department of the Environment, Water, Heritage and the Arts (DEWHA), 2009w) [Threat Abatement Plan].
Invasive and Other Problematic Species and Genes:Invasive and Other Problematic Species and Genes:unspecified Genoplesium rhyoliticum in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006lx) [Internet].
Invasive and Other Problematic Species and Genes:Problematic Native Species:Competition, grazing, predation and/or habitat degradation by mammals Genoplesium rhyoliticum in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006lx) [Internet].

Bishop, A. (1996). Field Guide to Orchids of New South Wales and Victoria. Sydney, NSW: University of New South Wales Press.

Elith, J. (2002). Predicting the distribution of plants. Ph.D. Thesis. School of Botany, University of Melbourne.

Jones, D.L. (1991b). New Taxa of Australian Orchidaceae. Australian Orchid Research. 2. Essendon: Australian Orchid Foundation.

Jones, D.L. (2001). Personal Communication.

Jones, D.L., M. Clements, I. Sharma, A. Mackenzie & B. Molloy (2002). Nomenclatural notes arising from studies into the Tribe Diurideae (Orchidaceae). Banks, D.P., ed. The Orchadian. 13 (10):437-468.

NSW National Parks & Wildlife Service (2003b). Recovery Plan for Threatened Flora of Rocky Outcrops in South Eastern New South Wales. [Online]. NSW National Parks & Wildlife Service. Hurstville, NSW January 2003. Available from:

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This database is designed to provide statutory, biological and ecological information on species and ecological communities, migratory species, marine species, and species and species products subject to international trade and commercial use protected under the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act). It has been compiled from a range of sources including listing advice, recovery plans, published literature and individual experts. While reasonable efforts have been made to ensure the accuracy of the information, no guarantee is given, nor responsibility taken, by the Commonwealth for its accuracy, currency or completeness. The Commonwealth does not accept any responsibility for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the information contained in this database. The information contained in this database does not necessarily represent the views of the Commonwealth. This database is not intended to be a complete source of information on the matters it deals with. Individuals and organisations should consider all the available information, including that available from other sources, in deciding whether there is a need to make a referral or apply for a permit or exemption under the EPBC Act.

Citation: Department of the Environment (2014). Genoplesium rhyoliticum in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: Accessed Thu, 17 Apr 2014 12:48:01 +1000.