''Caleana dixonii'', commonly known as the sandplain duck orchid is a rare species of

orchid Orchids are plants that belong to the family Orchidaceae (), a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Along with the Asteraceae, they are one of the two largest families of flowering ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the

south-west The points of the compass are a set of horizontal, radially arrayed compass directions (or azimuths) used in navigation and cartography. A compass rose is primarily composed of four cardinal directions—north, east, south, and west—each se ...

Western Australia Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...

. It has a single smooth leaf and a single greenish yellow and

fawn Deer or true deer are hoofed ruminant mammals forming the family Cervidae. The two main groups of deer are the Cervinae, including the muntjac, the elk (wapiti), the red deer, and the fallow deer; and the Capreolinae, including the reindeer ...

-coloured flower. It is distinguished by its flattened labellum with calli only near the tip of the labellum and its preference for growing on sandplains.

Description

''Caleana dixonii'' has a single smooth, dull green to dull red leaf, long and wide. The leaf is usually withered by flowering time. Usually only one greenish-yellow and fawn-coloured flower, long and wide is borne on a flowering stem high. The

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal co ...

sepal,

lateral Lateral is a geometric term of location which may refer to: Healthcare *Lateral (anatomy), an anatomical direction *Lateral cricoarytenoid muscle *Lateral release (surgery), a surgical procedure on the side of a kneecap Phonetics *Lateral cons ...

sepals and

petal Petals are modified Leaf, leaves that surround the reproductive parts of flowers. They are often advertising coloration, brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''c ...

s are narrow and hang downwards with the dorsal sepal pressed against the column which has broad wings, forming a bucket-like shape. About one-third of the outer part of the labellum is covered with glossy black

glands In animals, a gland is a group of cells in an animal's body that synthesizes substances (such as hormones) for release into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland). Structure De ...

or calli and the labellum has a flattened top. Flowering occurs from late October to early December.

Taxonomy and naming

The sandplain duck orchid was first formally described in 2006 by

Stephen Hopper Stephen Donald Hopper AC FLS FTSE (born 18 June 1951) is a Western Australian botanist. He graduated in Biology, specialising in conservation biology and vascular plants. Hopper has written eight books, and has over 200 publications to his n ...

and Andrew Brown who gave it the name ''Paracaleana dixonii''. The description was published in ''

Australian Systematic Botany ''Australian Systematic Botany'' is an international peer-reviewed scientific journal published by CSIRO Publishing. It is devoted to publishing original research, and sometimes review articles, on topics related to systematic botany, such as bio ...

''. 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 dixonii''. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

(''dixonii'') honours

Kingsley Dixon Kingsley Wayne Dixon (Ph.D.) is an Australian botanist currently working as a professor at Curtin University. He was the founding Director of Science at Kings Park and Botanic Gardens, and helped to establish the laboratories there as among t ...

, the science director at

Kings Park and Botanic Garden Kings Park, (Noongar: ''Kaarta Gar-up'') is a park overlooking Perth Water and the central business district of Perth, Western Australia. The park is a mixture of grassed parkland, botanical gardens and natural bushland on Mount Eliza with ...

, who was the first to recognise this species as distinct.

Distribution and habitat

''Caleana dixonii'' grows in sandy shrubland between Dongara and the

Moore River National Park Moore River National Park is a national park in the Wheatbelt region of Western Australia, 95 km north of Perth. The Moore River runs through the park on its way to the Indian Ocean where the township of Guilderton is situated. The park ...

in the

Geraldton Sandplains Geraldton (Wajarri: ''Jambinu'', Wilunyu: ''Jambinbirri'') is a coastal city in the Mid West region of the Australian state of Western Australia, north of the state capital, Perth. At June 2018, Geraldton had an urban population of 37,648. ...

and

Swan Coastal Plain The Swan Coastal Plain in Western Australia is the geographic feature which contains the Swan River as it travels west to the Indian Ocean. The coastal plain continues well beyond the boundaries of the Swan River and its tributaries, as a geol ...

biogeographic regions.

Conservation

''Caleana dixonii'' (as ''Paracaleana dixonii'') is classified as " Threatened Flora (Declared Rare Flora — Extant)" by the

Department of Environment and Conservation (Western Australia) The Department of Environment and Conservation (DEC) was a department of the Government of Western Australia that was responsible for implementing the state's conservation and environment legislation and regulations. It was formed on 1 July 2006 ...

References

External links

* * {{Taxonbar, from1=Q42705428 dixonii Orchids of Western Australia Endemic orchids of Australia Plants described in 2006 Endemic flora of Western Australia