''Caleana alcockii'', commonly known as Alcock's duck orchid
is a rare species of
orchid endemic 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 ...
of
Western Australia. It has a single smooth leaf and is distinguished by its humped
labellum and relatively late flowering period. It only occurs north of
Geraldton.
Description
''Caleana alcockii'' has a single smooth green or red leaf, long and wide. Usually only one greenish-yellow and red flower, about long and wide is borne on a thin, wiry stalk high. The
dorsal sepal,
lateral 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 or
calli and the labellum has a prominent hump at its centre. Flowering occurs from September to October.
Taxonomy and naming
Alcock's 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 alcockii''. The description was published in ''
Australian Systematic Botany''.
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 alcockii''.
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 ...
(''alcockii'') honours
John Alcock who recognised the species as distinct.
Distribution and habitat
''Caleana alcockii'' grows with grasses or
sedges in sandy soil in a small area north of the
Murchison River in the
Geraldton Sandplains biogeographic region
An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of l ...
.
Conservation
''Caleana alcockii'' (as ''Paracaleana alcockii'') is classified as "
Priority Two" by the Western Australian Government
Department of Parks and Wildlife
The Department of Parks and Wildlife (DPaW) was the department of the Government of Western Australia responsible for managing lands described in the ''Conservation and Land Management Act 1984'' and implementing the state's conservation and e ...
meaning that it is poorly known and from only one or a few locations.
References
{{Taxonbar, from1=Q42705425
alcockii
Orchids of Western Australia
Endemic orchids of Australia
Plants described in 2006
Endemic flora of Western Australia