Eriochilus

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Bunny orchid
Eriochilus dilatatus undulatus.jpg
Eriochilus dilatatus subsp. undulatus
Scientific classification
Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Orchidoideae
Tribe: Diurideae
Subtribe: Caladeniinae
Genus: Eriochilus
R.Br.
Synonyms[1]

Eriochilum Ritgen

Eriochilus, commonly known as bunny orchids, is a genus of flowering plants in the orchid family, Orchidaceae that is endemic to Australia. Orchids in this genus are distinguished from those in the similar Caladenia by having a glabrous leaf and a densely woolly labellum. Species occur in south-west Western Australia, South Australia, Queensland, New South Wales, the Australian Capital Territory, Victoria, and Tasmania. Their common name alludes to their prominent ear-like lateral sepals.

Description[edit]

Orchids in the genus Eriochilus are terrestrial, perennial, deciduous, sympodial herbs usually with a few inconspicuous, fine roots and a roughly spherical, succulent tuber. Replacement tubers form at the end of short "droppers". There is a single, glabrous, egg-shaped to lance-shaped leaf either at the base, or in the middle of the flowering stem.[2][3][4][5][6][7]

The inflorescence is a raceme with up to 25 resupinate flowers, each with a small bract at the base of its stalk. The dorsal sepal is smaller than the other two sepals, is dished and erect but curves forward to form a hood over the labellum. The lateral sepals are much longer, broader and more conspicuous than the dorsal sepal and are white to pink and spreading. As is usual in orchids, one petal is highly modified as the central labellum. The other two petals are usually smaller and narrower than the sepals and are either erect, spreading or curved backwards towards the ovary. The base of the labellum partly surrounds the lower part of the column forming a tube while the front is strongly curved downwards, covered with glandular hairs and often spotted. The sexual parts of the flower are fused to the column, which is erect, short, weakly curved and has narrow, wing-like structures. Bunny orchids flower from late winter to early summer, depending on species. The fruit that follows flowering is a non-fleshy, dehiscent capsule containing up to 500 seeds.[2][4][5][6][7]

Taxonomy and naming[edit]

The genus Eriochilus was first formally described in 1810 by Robert Brown and the description was published in Prodromus Florae Novae Hollandiae.[8][9] The botanical name Eriochilus is derived from the Ancient Greek words erion meaning "wool"[10]:864 and cheilos meaning lip[10]:486 referring to the hairy labellum.[2]

Distribution and habitat[edit]

Ten species of bunny orchids occur in Western Australia where they are found in a range of habitats from areas that are swampy in winter to dry inland woodlands. They occur from north of Kalbarri to Israelite Bay on the south coast.[2] Three species are found in the south-east of South Australia, including the Eyre Peninsula and Yorke Peninsula.[6][11] Two species are found in Victoria,[7] three in New South Wales. Bunny orchids are also found in Queensland and Tasmania.[5]

Species list[edit]

The following is a list of species recognised by the Australian Plant Name Index[12] and by Kew Gardens[1] (except that Kew has not yet included two species, E. collinus and E. paludosus described in 2016).

References[edit]

  1. ^ a b "Eriochilus". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew. Retrieved 25 June 2016. 
  2. ^ a b c d Hoffman, Noel; Brown, Andrew (2011). Orchids of South-West Australia. (3rd ed.). Gooseberry Hill: Noel Hoffman. pp. 220–231. ISBN 9780646562322. 
  3. ^ Pridgeon (ed.), Alec M.; Cribb (ed.), Phillip J.; Chase (ed.), Mark W.; Rasmussen (ed.), Finn (2001). Genera Orchidacearum, Volume 2, Orchidoideae (part 1). Oxford, England: Oxford University Press. pp. 113–115. ISBN 0198507100. 
  4. ^ a b "Elythranthera". FloraBase. Western Australian Government Department of Parks and Wildlife. 
  5. ^ a b c Bernhardt, Peter. "Eriochilus". Royal Botanic Garden Sydney: plantnet. Retrieved 26 June 2016. 
  6. ^ a b c "Eriochilus". State Herbarium of South Australia: efloraSA. Retrieved 26 June 2016. 
  7. ^ a b c "Eriochilus". Royal Botanic Gardens Victoria: vicflora. Retrieved 26 June 2016. 
  8. ^ "Eriochilus". APNI. Retrieved 26 June 2016. 
  9. ^ Brown, Robert (1810). Prodromus Florae Novae Hollandiae. London. p. 323. Retrieved 26 June 2016. 
  10. ^ a b Brown, Roland Wilbur (1956). The Composition of Scientific Words. Washington, D.C.: Smithsonian Institution Press. 
  11. ^ "Eriochilus". Atlas of Living Australia. Retrieved 26 June 2016. 
  12. ^ "Australian Plant Name Index". Council of Heads of Australian Herbaria. Retrieved 26 June 2016.