Genoplesium acuminatum

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Pointed midge orchid
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Orchidoideae
Tribe: Diurideae
Genus: Genoplesium
Species:
G. acuminatum
Binomial name
Genoplesium acuminatum
Synonyms[1]

Genoplesium acuminatum, commonly known as the pointed midge orchid,[2] is a small terrestrial orchid endemic to eastern Australia. It has a single thin leaf fused to the flowering stem and up to sixteen small, hairy, greenish purple to brownish purple flowers. It is found in coastal and near-coastal parts of New South Wales and Queensland.

Description[edit]

Genoplesium acuminatum is a terrestrial, perennial, deciduous, herb with an underground tuber and a single thin leaf 100–350 mm (4–10 in) long and fused to the flowering stem with the free part 15–30 mm (0.6–1 in) long. Between six and sixteen greenish purple to brownish purple flowers are crowded along a flowering stem 20–60 mm (0.8–2 in) tall and taller than the leaf. The flowers are about 8 mm (0.3 in) long and 6 mm (0.2 in) wide and are inverted so that the labellum is above the column rather than below it. The dorsal sepal is broadly egg-shaped, about 4 mm (0.16 in) long and 2 mm (0.08 in) wide with long, coarse hairs on its edges. The lateral sepals are linear to lance-shaped, about 5 mm (0.2 in) long, 1.5 mm (0.06 in) wide, have pointed tips and spread widely apart from each other. The petals are lance-shaped to broad egg-shaped, about 3.5 mm (0.1 in) long and 1.5 mm (0.06 in) wide with hairy edges and a sharply pointed tip. The labellum is lance-shaped to egg-shaped, about 3 mm (0.1 in) long, 1.5 mm (0.06 in) wide, with a curled, sharply pointed tip and long, coarse hairs on the sides. There is an oblong callus in the centre of the labellum and extending about half way to its tip. Flowering occurs between December and May.[2][3]

Taxonomy and naming[edit]

The pointed midge orchid was first formally described in 1927 by Richard Sanders Rogers who gave it the name Prasophyllum acuminatum and published the description in Transactions and Proceedings of the Royal Society of South Australia.[4][5] In 1989, David Jones and Mark Clements changed the name to Genoplesium acuminatum[6] and in 1998 changed the name again to Corunastylis acuminata,[7] but the latter name change is not accepted by Plants of the World Online.[1] The specific epithet (acuminatum) is a Latin word meaning "sharpened" or "pointed".[8]

Distribution and habitat[edit]

Genoplesium acuminatum grows in forest in coastal and near-coastal areas of New South Wales from near Sydney north to Fraser Island in Queensland.[2][3]

References[edit]

  1. ^ a b c "Genoplesium acuminatum". Plants of the World Online. Retrieved 5 August 2023.
  2. ^ a b c Jones, David L. (2006). A complete guide to native orchids of Australia including the island territories. Frenchs Forest, N.S.W.: New Holland. pp. 175–176. ISBN 1877069124.
  3. ^ a b Jones, David L. "Genoplesium acuminatum". Royal Botanic Garden Sydney. Retrieved 23 January 2018.
  4. ^ "Prasophyllum acuminatum". APNI. Retrieved 23 January 2018.
  5. ^ Rogers, Richard S. (1927). "Contribution to the Orchidology of Australia". Transactions and Proceedings of the Royal Society of South Australia. 51: 291–292. Retrieved 23 January 2018.
  6. ^ "Genoplesium acuminatum". APNI. Retrieved 23 January 2018.
  7. ^ "Corunastylis acuminata". APNI. Retrieved 23 January 2018.
  8. ^ Brown, Roland Wilbur (1956). The Composition of Scientific Words. Washington, D.C.: Smithsonian Institution Press. p. 621.