Indicative distribution
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: Genoplesium plumosum
Gazetted date:
18 Jul 1997
Profile last updated:
21 Sep 2021
Description
The Tallong Midge Orchid produces a single flowering stem, usually 10 -20 cm high, but occasionally to 30 cm high. A clusters of 1-6 flowers are produced at the top of each stem. Individual flowers are approximately 8 mm across and are green, with pinkish-purple stripes. Flowers appear in late summer to autumn after heavy rainfall. The labellum (petal ‘lip’ in the centre of the flower) has long hairs. When not in flower, only a single, thin, green leaf is present above the ground; this is indistinguishable from the leaves of other midge orchids. Its habitat is a useful identifier. Genoplesium is a genus of relatively inconspicuous ground orchids with clustered spikes of dark-coloured flowers that are non-resupinate (i.e. they are ‘upside down’ relative to most other orchids) and have a single flat, not tubular, leaf. This leaf distinguishes them from the very similar genus Prasophyllum, the leek orchids, their closest relatives.
Distribution
The Tallong Midge Orchid was originally collected at Kurnell in 1947; presumably it also occurred south of there, but it is now only known from two areas - the village of Tallong and its immediate environs, and a site in Morton National Park 8.5 km south-east of the town of Wingello. At Tallong it occurs within an area of less than two kilometres north and east of the town centre and the largest population of flowering plants that has been recorded (in 2001) is less than 300 plants. The Morton National Park site was discovered in 2001 and there were only 10 flowering plants at that time. Surveys have failed to locate any plants there since then.
Habitat and ecology
- Occurs exclusively in heathland, generally dominated by Violet Kunzea (Kunzea parvifolia), Common Fringe-myrtle (Calytrix tetragona) and parrot-peas (Dillwynia spp.).
- Grows on very shallow soils, often with lichens and mosses on sandstone conglomerate rock shelves.
- Plants exists only as a dormant tuber for much of the year, with leaves or fruiting stems dying back in late winter.
- Flowering stems emerge from late February to March, depending on the seasonal condiitons, and they develop to flowering stage within about four weeks.
- Plants do not flower every year and often produce only a leaf. Leaves usually emerge a few weeks later than the stems that will produce flowers.
- Following flowering numerous fine dust like seeds develop in fleshy capsules which take several weeks to mature. After the capsules split and shed the seed the capsules remain on the old stems for up to a few months.
- Reproduction is by seed only and the species has no mechanism for vegetative reproduction.
- While the pollination biology of this species is not known, most midge orchids are pollinated by vinegar flies, although some are self-pollinating.
Regional distribution and habitat
Click on a region below to view detailed distribution, habitat and vegetation information.
Threats
- Loss, degradation and fragmentation of habitat and / or populations for residential developments. This species can be difficult to survey as flowering is highly dependent on seasonal conditions and there is a high risk of failure to detect the species at some proposed development sites.
- Loss and degradation of habitat and/or populations from road works (particularly widening or rerouting).
- Any species with such a small range and population size is vulnerable to disturbance (e.g. fire, drought, disturbances), and the loss of even a few plants can be of major significance.
- Damage from recreational vehicles.
- Heavy browsing, possibly by wallabies or possums.
- Most sites are on private land. Although some of the current owners are supportive of protecting this species, future owners of the properties may not be as sympathetic to the protection of the species.
- Some accessible sites have shown evidence of illegal collection.
Recovery strategies
A targeted strategy for managing this species has been developed under the Saving Our Species program; click
here for details. For more information on the Saving Our Species program click
here
Activities to assist this species
- Consent authorities are encouraged to ensure that residential dwellings are placed so as to avoid direct and indirect impacts on Tallong Midge Orchid plants and its habitat.
- Develop management agreements with landowners to ensure the species is managed sustainably on private land.
- Monitor known populations to detect any decline or new threat. Control any threats that may be detected.
- Mark sites and potential habitat onto maps used for planning (road works and residential developments, rehabilitation and recovery).
- Search for new populations in potential habitat; surveys should be conducted in good flowering seasons when recorded populations are known to be flowering.
Information sources
- Bishop, T. (2000) Field Guide to the Orchids of New South Wales and Victoria. (New South Wales University Press, Sydney)
- Harden, G.J. (ed.) (1993) Flora of New South Wales Vol. 4. UNSW Press, Kensington, NSW.
- NSW National Parks and Wildlife Service (2002) Genoplesium plumosum (a terrestrial orchid) Recovery Plan. NSW NPWS, Hurstville NSW.
- NSW Scientific Committee (1997) Genoplesium plumosum (a terrestrial orchid) - Endangered species determination - final. DEC (NSW), Sydney.
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