Octarrhena, commonly known as grub orchids,[3] is a genus of flowering plants from the orchid family, Orchidaceae. Plants in this genus are small, orchids with short stems, thin roots, short, thick, fleshy leaves arranged in two ranks and tiny flowers. The labellum is rigidly attached to the base of the column. There are about fifty species native to areas from Sri Lanka and Malesia to the Western Pacific.

Octarrhena
Illustration of Phreatia nana (now known as Octarrhena parvula) from Hooker's Icones Plantarum[2]
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Epidendroideae
Tribe: Podochileae
Subtribe: Thelasiinae
Genus: Octarrhena
Thwaites[1]
Type species
Octarrhena parvula
Thwaites
Synonyms[1]

Description

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Orchids in the genus Octarrhena are small epiphytic, lithophytic or terrestrial herbs with thin roots and short stems with short, thick, fleshy leaves, their bases sheathing the stem. A large number of tiny, usually white, cream-coloured, yellowish or greenish flowers are arranged on a flowering stem arising from a leaf axil. The sepals and petals are free from each other, the petals usually much smaller than the sepals. The labellum is small, unlobed, rigidly fixed to the column and lacks a spur.[3][4][5]

Taxonomy and naming

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The genus Octarrhena was first formally described in 1861 by George Henry Kendrick Thwaites who published the description in Enumeratio plantarum Zeylaniae.[1][6] The name Octarrhena is derived from the Ancient Greek words okto meaning "eight"[7]: 296  and arrhen meaning "male" or "masculine",[7]: 509  referring the eight free pollinia in the anther.[4]

Species list

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The following is a list of species of Octarrhena recognised by the World Checklist of Selected Plant Families as at January 2019:[1]

Distribution

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Orchids in the genus Octarrhena are found in Sri Lanka, Vietnam, Borneo, Java, Peninsular Malaysia, the Philippines, Sulawesi, Sumatra, the Bismarck Archipelago, New Guinea, the Solomon Islands, Queensland (Australia), Fiji, New Caledonia, Vanuatu and the Caroline Islands.[1]

References

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  1. ^ a b c d e "Octarrhena". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew.
  2. ^ Hooker, William J. (1892). Icones Plantarum. Vol. 21. London. p. 2084. Retrieved 17 June 2021.{{cite book}}: CS1 maint: location missing publisher (link)
  3. ^ a b Jones, David L. (2006). A complete guide to native orchids of Australia including the island territories. Frenchs Forest, N.S.W.: New Holland. p. 471. ISBN 1877069124.
  4. ^ a b D.L.Jones; T.Hopley; S.M.Duffy (2010). "Octarrhena". Australian Tropical Rainforest Orchids. Centre for Australian National Biodiversity Research (CANBR), Australian Government. Retrieved 28 May 2021.
  5. ^ "Genus Octarrhena". Orchids of New Guinea. Retrieved 16 January 2019.
  6. ^ Thwaites, George H.K. (1861). Enumeratio plantarum Zeylaniae. London: Dulau & Co. p. 305. Retrieved 16 January 2019.
  7. ^ a b Brown, Roland Wilbur (1956). The Composition of Scientific Words. Washington, D.C.: Smithsonian Institution Press.
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