| Dark midge orchid | |
|---|---|
| Conservation status | |
 Critically endangered (EPBC Act) | |
Scientific classification 
| |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Monocots |
| Order: | Asparagales |
| Family: | Orchidaceae |
| Subfamily: | Orchidoideae |
| Tribe: | Diurideae |
| Genus: | Genoplesium |
| Species: | G. insigne |
| Binomial name | |
| Genoplesium insigne D.L.Jones | |
| Synonyms | |
|
Corunastylis insignis (D.L.Jones) D.L.Jones & M.A.Clem. | |
Genoplesium insigne, commonly known as the dark midge orchid or Wyong midge orchid, is a species of small terrestrial orchid that is endemic to New South Wales. It has a single thin leaf and up to twelve dark purple to dark reddish purple flowers. It is mostly found in heath on the Central Coast and only around fifty plants survive.
Description
Genoplesium insigne is a terrestrial, perennial, deciduous, herb with an underground tuber and a single thin, dark green leaf with a reddish base. The leaf is 60–150 mm (2–6 in) long, about 1.5 mm (0.06 in) wide with the free part 10–15 mm (0.4–0.6 in) long. Between five and twelve dark purple to dark reddish purple flowers are arranged along a flowering stem 90–180 mm (4–7 in) tall and taller than the leaf. The flowers are about 5 mm (0.2 in) wide and as with others in the genus, are inverted so that the labellum is above the column rather than below it. The dorsal sepal is lance-shaped to egg-shaped, 5–5.5 mm (0.20–0.22 in) long, 2.5 mm (0.1 in) wide and concave. The lateral sepals are linear to lance-shaped, 6.5–7 mm (0.26–0.28 in) long, about 1 mm (0.04 in) wide and more or less parallel to each other. The petals are lance-shaped to narrow egg-shaped, 4.5–5 mm (0.18–0.20 in) long and 1 mm (0.04 in) wide. The labellum is egg-shaped to elliptic, about 4 mm (0.2 in) long, 2 mm (0.08 in) wide with purple hairs up to 1 mm (0.04 in) long on the sides. There is a fleshy, dark purplish black callus in the centre of the labellum and covering less than half of it. Flowering occurs between August and November.
Taxonomy and naming
Genoplesium insigne was first formally described in 2001 by David Jones who published the description in The Orchadian from a specimen collected in the Lake Macquarie State Recreation Area. In 2002, Jones and Mark Clements changed the name to Corunastylis insignis but the change is not accepted by the Australian Plant Census. The specific epithet (insigne) is a Latin word meaning "remarkable", "eminent" or "distinguished".
Distribution and habitat
The dark midge orchid grows in heath and heathy forest, in four small areas between Chain Valley Bay and Wyong with a further small population near Lake Macquarie.
Conservation
It is difficult to determine the precise number of plants of the G. insigne because they are difficult to locate and weather conditions affect whether or not the plants flower. There are estimated to be around fifty plants surviving. The species is classed as "Critically Endangered" under the New South Wales Threatened Species Conservation Act and the Commonwealth Government Environment Protection and Biodiversity Conservation Act 1999 (EPBC) Act. The main threats to the species are weed invasion, habitat disturbance, grazing by rabbits and illegal collecting.
References
- ^ "Genoplesium insigne". Australian Plant Census. Retrieved 13 July 2021.
- Jones, David L. (2006). A complete guide to native orchids of Australia including the island territories. Frenchs Forest, N.S.W.: New Holland. p. 180. ISBN 1877069124.
- Jones, David. "Genoplesium insigne". Royal Botanic Garden Sydney. Retrieved 3 February 2018.
- ^ "NSW Scientific Committee - Final determination: Genoplesium insigne" (PDF). Government of New South Wales. Retrieved 3 February 2018.
- ^ "Conservation advice - Corunastylis insignis Wyong midge orchid" (PDF). Australian Government Department of the Environment. Retrieved 3 February 2018.
- "Genoplesium insigne". APNI. Retrieved 3 February 2018.
- "Corunastylis insignis". APNI. Retrieved 3 February 2018.
- Lewis, Charlton T.; Short, Charles (1879). A Latin dictionary. Oxford University Press. Retrieved 3 February 2018.
- ^ "Variable midge orchid - profile Genoplesium insigne". New South Wales Government Office of Environment and Heritage. Retrieved 3 February 2018.