Biology:Pterostylis mutica

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Short description: Species of orchid


Midget greenhood
Pterostylis mutica (2).jpg
Pterostylis mutica growing near Lake King, Western Australia
Scientific classification edit
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Orchidoideae
Tribe: Cranichideae
Genus: Pterostylis
Species:
P. mutica
Binomial name
Pterostylis mutica
R.Br.[1]
Synonyms[1]
  • Oligochaetochilus muticus (R.Br.) Szlach.
  • Hymenochilus muticus (R.Br.) D.L.Jones & M.A.Clem.

Pterostylis mutica, commonly known as the midget greenhood, is a plant in the orchid family Orchidaceae and is endemic to Australia , occurring in all states but not the Northern Territory. There is a rosette of leaves at the base of the flowering stem and up to fifteen pale green flowers which have a sensitive labellum.

Labelled image of P. mutica

Description

Pterostylis mutica, is a terrestrial, perennial, deciduous, herb with an underground tuber. There is a rosette of between six and twelve, egg-shaped leaves, each leaf 10–30 mm (0.4–1 in) long and 5–15 mm (0.2–0.6 in) wide at the base of the plant. Between two and twenty well-spaced flowers are borne on a flowering spike 150–350 mm (6–10 in) high with five to ten stem leaves wrapped around it. The flowers are pale green, 8–10 mm (0.3–0.4 in) long and about 5 mm (0.2 in) wide. The dorsal sepal and petals are joined to form a hood called the "galea" over the column. The galea is curved with a pointed tip turning downwards. The lateral sepals turn downwards and are about 7 mm (0.3 in) long, 8 mm (0.3 in) wide, cupped and joined for most of their length. The labellum is about 4 mm (0.2 in) long, about 2 mm (0.08 in) wide and whitish-green with a dark green appendage. Flowering occurs from July to December.[2][3][4][5][6][7]

Taxonomy and naming

Pterostylis mutica was first formally described in 1810 by Robert Brown from a specimen collected near Port Jackson and the description was published in Prodromus Florae Novae Hollandiae et Insulae Van Diemen.[1] The specific epithet (mutica) is a Latin word meaning "shortened" or "docked"[8] referring to the blunt petals and sepals.[6]

Distribution and habitat

Pterostylis mutica is widespread and often common, growing in a wide range of habitats from near the coast to mountains, but usually in well-drained soil. It tolerates dry conditions, poor soil and exposed positions. It is widespread in New South Wales and Victoria and also occurs in south-east Queensland, south-eastern South Australia and the south-west of Western Australia. There is doubt about its presence in Tasmania[2][3][4][7][9][10]

Ecology

The labellum of P. mutica is attractive to a species of gnat which lands on the labellum and grasps the dark green appendage. When it does so, the labellum springs upward, trapping the insect inside the now-closed flower. The gnat can now only escape by pushing between "wings" on the sides of the column. As it does so, it either removes a pollinium or deposits one from a previously visited flower of the same species, and pollination occurs.[11]

References

  1. 1.0 1.1 1.2 "Pterostylis mutica". APNI. https://id.biodiversity.org.au/instance/apni/487802. Retrieved 21 May 2017. 
  2. 2.0 2.1 Jones, David L. (2006). A complete guide to native orchids of Australia including the island territories. Frenchs Forest, N.S.W.: New Holland. p. 321. ISBN 978-1877069123. 
  3. 3.0 3.1 Jeanes, Jeff. "Pterostylis mutica". Royal Botanic Gardens Victoria: vicflora. https://vicflora.rbg.vic.gov.au/flora/taxon/035af963-7843-4d1a-a823-ffa7f4cf8807. Retrieved 13 May 2017. 
  4. 4.0 4.1 Jones, David L.. "Pterostylis mutica". Royal Botanic Gardens Sydney: plantnet. http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Pterostylis~mutica. Retrieved 21 May 2017. 
  5. "Pterostylis mutica". State Herbarium of South Australia: eflora SA. http://www.flora.sa.gov.au/cgi-bin/speciesfacts_display.cgi?form=speciesfacts&family=&genus=Pterostylis&species=mutica&iname=&submit=Display. Retrieved 21 May 2017. 
  6. 6.0 6.1 Brown, Andrew; Dundas, Pat; Dixon, Kingsley; Hopper, Stephen (2008). Orchids of Western Australia. Crawley, Western Australia: University of Western Australia Press. p. 374. ISBN 9780980296457. 
  7. 7.0 7.1 Hoffman, Noel; Brown, Andrew (2011). Orchids of South-West Australia (3rd ed.). Gooseberry Hill: Noel Hoffman. p. 418. ISBN 9780646562322. 
  8. Brown, Roland Wilbur (1956). The Composition of Scientific Words. Washington, D.C.: Smithsonian Institution Press. p. 428. 
  9. "Pterostylis mutica". FloraBase. Western Australian Government Department of Parks and Wildlife. https://florabase.dpaw.wa.gov.au/browse/profile/1689. 
  10. Jones, David L. (1998). "A taxonomic review of Pterostylis in Tasmania". Australian Orchid Research 3: 146–147. 
  11. Cingel, Nelis A. van der (2000). An atlas of orchid pollination : America, Africa, Asia and Australia. Rotterdam: Balkema. p. 210. ISBN 978-9054104865. 

Wikidata ☰ Q15497032 entry