Caleana terminalis, commonly known as smooth-billed duck orchid[3] is a species of orchid endemic to a small area near the Murchison River in the south-west of Western Australia. It has a single smooth leaf and usually only a single greenish yellow and red flower. It is distinguished by its slightly humped labellum, with calli only on its outer one fifth.

Smooth-billed duck orchid
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Orchidoideae
Tribe: Diurideae
Genus: Caleana
Species:
C. terminalis
Binomial name
Caleana terminalis
Synonyms[2]

Description

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Caleana terminalis has a single smooth, dull green or dull red leaf, 20–30 mm (0.8–1 in) long and 5–7 mm (0.2–0.3 in) wide. Unlike those of most other caleanas, the leaf is not withered at flowering time. Usually only one greenish yellow and red flower, 15–22 mm (0.6–0.9 in) long and 10–14 mm (0.4–0.6 in) wide is borne on a thin, wiry stalk 80–140 mm (3–6 in) high. The dorsal sepal, lateral sepals and petals are narrow and hang downwards with the dorsal sepal pressed against the column which has broad wings, forming a bucket-like shape. About one fifth of the outer part of the labellum is covered with glossy black glands or calli and the labellum has a slightly humped top. Flowering occurs in August and September.[3][4]

Taxonomy and naming

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The smooth-billed duck orchid was first formally described in 2006 by Stephen Hopper and Andrew Brown who gave it the name Paracaleana terminalis. The description was published in Australian Systematic Botany from a specimen collected from the Z Bend in the Murchison River Gorge near Kalbarri.[5] In 2014, based on molecular studies, Joseph Miller and Mark Clements transferred all the species previously in Paracaleana to Caleana so that the present species became Caleana terminalis.[1][6] The specific epithet (terminalis) is a Latin word meaning "of ends or boundaries",[7] referring to the callus being confined to the very tip of the labellum.[3][4]

Distribution and habitat

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Caleana terminalis grows in sandy soil in shrubland between the Pinjarega Nature Reserve and Nerren Nerren station in the Geraldton Sandplains biogeographic region.[3][4][8]

Conservation

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Caleana terminalis (as Paracaleana terminalis) is classified as "not threatened" by the Western Australian Government Department of Parks and Wildlife.[8]

References

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  1. ^ a b "Caleana terminalis". APNI. Retrieved 25 April 2018.
  2. ^ "Caleana terminalis". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew.
  3. ^ a b c d Hoffman, Noel; Brown, Andrew (2011). Orchids of South-West Australia (3rd ed.). Gooseberry Hill: Noel Hoffman. p. 251. ISBN 9780646562322.
  4. ^ a b c Brown, Andrew; Dundas, Pat; Dixon, Kingsley; Hopper, Stephen (2008). Orchids of Western Australia. Crawley, Western Australia: University of Western Australia Press. p. 304. ISBN 9780980296457.
  5. ^ "Paracaleana terminalis". APNI. Retrieved 25 April 2018.
  6. ^ Miller, Joseph T.; Clements, Mark A. (2014). "Molecular phylogenetic analyses of Drakaeinae: Diurideae (Orchidaceae) based on DNA sequences of the internal transcribed spacer region". Australian Systematic Botany. 27 (1): 3–22. doi:10.1071/SB13036. Retrieved 25 April 2018.
  7. ^ Brown, Roland Wilbur (1956). The Composition of Scientific Words. Washington, D.C.: Smithsonian Institution Press. p. 301.
  8. ^ a b "Paracaleana terminalis". FloraBase. Western Australian Government Department of Biodiversity, Conservation and Attractions.
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