Pterostylis metcalfei

Pterostylis metcalfei, commonly known as Metcalfe's greenhood, the large kinked greenhood orchid or Ebor greenhood is a species of orchid which is endemic to the Northern Tablelands of New South Wales. As with similar greenhoods, the flowering plants differ from those which are not flowering. The non-flowering plants have a rosette of leaves flat on the ground but the flowering plants have a single flower with leaves on the flowering spike. This greenhood has a dark green and white striped flower and is known from only three locations. It is therefore listed as an endangered species.

Metcalfe's greenhood
Pterostylis metcalfei growing near Ebor
Scientific classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Orchidoideae
Tribe: Cranichideae
Genus: Pterostylis
Species:
P. metcalfei
Binomial name
Pterostylis metcalfei
Synonyms[2]
  • Diplodium metcalfei (D.L.Jones) D.L.Jones & M.A.Clem.

Description

Pterostylis metcalfei has a rosette of 3 to 5 leaves, each leaf 7–30 mm (0.3–1 in) long, 7–20 mm (0.3–0.8 in) wide, dark green and flat.[3][4]

The flower stem is 10–30 cm (4–10 in)1 long and bears a single flower 23–28 mm (0.9–1 in) long and 9–11 mm (0.35–0.43 in) wide and shiny, greenish-white with darker green stripes. The dorsal sepal is erect at its base but then arches forward, forming a hood over the labellum and has a threadlike tip, 7–14 mm (0.3–0.6 in) long. The labellum is blunt, sharply kinked in the middle and is 13.5–17 mm (0.53–0.67 in) long and about 3 mm (0.1 in) wide. Flowering occurs from March to May.[3][4]

Front view of Pterostylis metcalfei

Taxonomy and naming

Pterostylis metcalfei was first formally described by David L. Jones in 1997 from a specimen collected by Peter Metcalfe on Doughboy Mountain, about 10 km (6 mi) south of Wongwibindi station, on the road to Wollomombi, on 8 May 1994. The description was published in The Orchadian.[1] In 2002, Jones and Clements transferred the species to the genus Diplodium[2][5] but the move has not been accepted by the National Herbarium of New South Wales[6] nor by the Royal Botanic Gardens, Kew.[7] The specific epithet (metcalfei) honours the collector of the type specimen, Peter Metcalfe.

Distribution and habitat

The species is endemic to the New England Tablelands (biogeographic region) at altitudes of 1,000 to 1,350 m (3,000 to 4,000 ft). It is found on ridges and slopes with well drained soil derived from granite and basalt, growing among grass and shrubs.[3] It is known from only three locations, only one of which is in a national park, so that it is threatened by cattle grazing and trampling.[8]

Conservation status

The Scientific Committee of the Office of Environment and Heritage, established by the Threatened Species Conservation Act, has listed P. metcalfei as an Endangered Species on Part 1 of Schedule 1 of the Threatened Species Conservation Act.[8]

References
  1. "Pterostylis metcalfei". APNI. Retrieved 5 June 2016.
  2. "Diplodium metcalfei". APNI. Retrieved 5 June 2016.
  3. Jones, David L. (2006). A Complete Guide to Native Orchids of Australia including the Island Territories. Frenchs Forest, N.S.W.: New Holland. p. 289. ISBN 978-1877069123.
  4. "Metcalfe's Greenhood - profile". NSW Government Department of Environment and Heritage. Retrieved 16 June 2016.
  5. Jones, David L.; Clements, Mark A. (2002). A Review of Pterostylis (Orchidaceae). Essendon, Vic.: Australian Orchid Foundation. ISBN 978-0642549044.
  6. "Pterostylis metcalfei". Royal Botanic Garden Sydney; plantnet. Retrieved 6 June 2016.
  7. "Diplodium metcalfei". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew.
  8. "Pterostylis metcalfei (a terrestrial orchid) - endangered species listing". : Office of Environment and Heritage. Retrieved 27 January 2015.
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