Dipodium

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Hyacinth orchids
Dipodium punctatum fir00002.jpg
Dipodium punctatum
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Epidendroideae
Tribe: Cymbidieae
Subtribe: Cymbidiinae[1]
Alliance: Dipodium
Genus: Dipodium
Type species
Dipodium punctatum[2]
Species

see text

Synonyms[3]

Dipodium, commonly known as hyacinth orchids,[4] is a genus of about forty species of orchids native to tropical, subtropical and temperate regions of south-east Asia, New Guinea, the Pacific Islands and Australia. It includes both terrestrial and climbing species, some with leaves and some leafless, but all with large, often colourful flowers on tall flowering stems. It is the only genus of its alliance, Dipodium.

Description[edit]

Orchids in the genus Piplodium are perennial, terrestrial herbs or climbers/epiphytes. Many species, particularly in eastern Australia are leafless mycoheterotrophs. Others have medium-sized to very large leaves that are parallel-veined and have entire margins. The flowers are arranged in a raceme with very few or up to fifty large, often colourful flowers. These may be fragrant or odourless, are white, pink, purple, yellow or green, often with spots or blotches. The sepals and petals are free from and similar to each other. The labellum projects forwards and has three lobes with a central band of colourful hairs. Each flower has two pollinia that are supported on two stipes. Dehiscent capsules, produced after flowering, hold the seed which is released when the capsule splits longitudinally along six seams. Between 30 and 500 seeds are produced per capsule.[4][5][6][7]

Taxonomy[edit]

The genus was formally described in 1810 by Scottish botanist Robert Brown in Prodromus Florae Novae Hollandiae et Insulae Van Diemen.[2][8] The name Dipodium is derived the Greek words di (two) and podia (little feet), a reference to the two stipes supporting the pollinia.[9]

Two flowering scapes of a leafless species in south-eastern Australia

Distribution and habitat[edit]

Hyacinth orchids are found in Malaysia, the Philippines, Indonesia, the Solomon Islands, the New Hebrides, New Caledonia, New Guinea and Australia where eleven species are endemic. They occur in a range of habitats from coastal lowlands to ranges and tablelands.[4][10]

Ecology[edit]

It is thought that the flowers attract native bees and wasps through floral mimicry.[11]

Uses[edit]

An infusion of the leaves of Dipodium pandanum is traditionally drunk in Bouganville to help relieve respiratory infections.[12]

Use in horticulture[edit]

Leafless hyacinth orchids are impossible to grow in cultivation but D. pandanum is easy to grow in warm climates.[4]:272

Cultural references[edit]

A hyacinth orchid is the subject of the poem The Aboriginal Axe by Australian poet Douglas Stewart. In the poem, Stewart refers to the flowers as "lovely and leprous, flushed and spotted".[13]

Species[edit]

The following is a list of described species in the genus Dipodium, recognised by the World Checklist of Selected Plant Families[3] apart from Dipodium punctatum which is recognised as a species in Australia (rather than as a synonym of Dipodium squamatum).[2][14]

Undescribed species[edit]

  • Dipodium sp. Basalt Woodland (M.D. Barrett 198) - northern Kimberley, Western Australia.[15]
  • Dipodium sp. Sandstone (R.L. Barrett & K.W. Dixon 1642) - northern Kimberley,[16]

External links[edit]

  • Media related to Dipodium at Wikimedia Commons

References[edit]

  1. ^ "Dipodium R.Br". The Orders and Families of Monocots. eMonocot. Retrieved 18 April 2014.
  2. ^ a b c d "Dipodium". APNI. Retrieved 12 July 2018.
  3. ^ a b "Dipodium". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew. Retrieved 12 July 2018.
  4. ^ a b c d Jones, David L. (2006). A complete guide to native orchids of Australia including the island territories. Frenchs Forest, N.S.W.: New Holland. p. 270. ISBN 1877069124.
  5. ^ "Dipodium R.Br". FloraBase. Western Australian Government Department of Parks and Wildlife.
  6. ^ Weston, P.H. "Genus Dipodium". PlantNET - New South Wales Flora Online. Royal Botanic Gardens & Domain Trust, Sydney Australia. Retrieved 7 February 2014.
  7. ^ Jeanes, Jeff. "Dipodium". Royal Botanic Gardens Victoria. Retrieved 12 July 2018.
  8. ^ Brown, Robert (1810). Prodromus Florae Novae Hollandiae et Insulae Van Diemen. London. pp. 330–331. Retrieved 12 July 2018.
  9. ^ Clements, Mark A (2013). The Allure of Orchids. National Library Australia. pp. 48–51. ISBN 978-0-642-27807-4.
  10. ^ Jones, David L. (1991). "New taxa of Australian Orchidaceae". Australian Orchid Research. 2: 48.
  11. ^ Jessup, Scott. "Action statement - yellow hyacinth orchid Dipodium hamiltonianum" (PDF). The State of Victoria, Department of Sustainability and Environment. Retrieved 12 July 2018.
  12. ^ Lawler, L.J.; Slaytor, M. (1969). "The distribution of alkaloids in orchids from the territory of Papua and New Guinea". Proceedings of the Linnean Society of New South Wales. 94: 240. Retrieved 8 February 2014.
  13. ^ Stewart, Douglas. "The Aboriginal Axe". Australian Poetry Library.
  14. ^ "Dipodium punctatum". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew. Retrieved 12 July 2018.
  15. ^ "Dipodium sp. Basalt Woodland (M.D. Barrett 198)". FloraBase. Western Australian Government Department of Parks and Wildlife.
  16. ^ "Dipodium sp. Sandstone (R.L. Barrett & K.W. Dixon 1642)". FloraBase. Western Australian Government Department of Parks and Wildlife.