''Caladenia dorrienii'', commonly known as the Cossack spider orchid, is a 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 ...

of Western Australia. It has a single hairy leaf and one, two or sometimes three small creamy-white flowers, usually with the lateral

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

s 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 curving around the

ovary The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. ...

and crossing each other. It is a rare orchid, only found in the extreme south-east of the state.

Description

''Caladenia dorrienii'' is a terrestrial,

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, aft ...

herb In general use, herbs are a widely distributed and widespread group of plants, excluding vegetables and other plants consumed for macronutrients, with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal ...

with an underground tuber and which grows in clumps. It has a single, erect, narrow linear, hairy leaf, long and wide. One, two or sometimes three white to creamy-white flowers are borne on a stalk tall. The flowers are long and wide. The sepals and petals are relatively short, greenish-white with red lines and dark glandular tips. The dorsal sepal is erect and the lateral sepals and petals usually curve downwards and cross each other. The labellum is pale white, relatively broad and has smooth to slightly toothed edges. Along its centre line there are two rows of white or pale red-tipped calli. Flowering occurs from September to November.

Taxonomy and naming

''Caladenia dorrienii'' was first formally described by Karel Domin in 1912 from a specimen collected by

Arthur Dorrien-Smith Major Arthur Algernon Dorrien-Smith (28 January 1876 – 30 May 1955) was Lord Proprietor of the Isles of Scilly from 1918 to 1920. Family Major Arthur Algernon Smith-Dorrien-Smith was born on 28 January 1876, in Oxfordshire, to Thomas Smith ...

near

Bridgetown Bridgetown (UN/LOCODE: BB BGI) is the capital and largest city of Barbados Barbados is an island country in the Lesser Antilles of the West Indies, in the Caribbean region of the Americas, and the most easterly of the Caribbean Island ...

. The description was published in Journal of the Linnean Society, Botany. 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 ...

(''dorrienii'') honours the collector of the

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * Ty ...

specimen.

Distribution and habitat

The Cossack spider orchid is only found in scattered communities between Kojonup and Boyup Brook and near West Dale in the Avon Wheatbelt and

Jarrah Forest Jarrah forest is tall open forest in which the dominant overstory tree is ''Eucalyptus marginata'' (jarrah). The ecosystem occurs only in the Southwest Botanical Province of Western Australia. It is most common in the biogeographic region named in ...

biogeographic regions A biogeographic realm or ecozone is the broadest biogeographic division of Earth's land surface, based on distributional patterns of terrestrial organisms. They are subdivided into bioregions, which are further subdivided into ecoregions. De ...

where it grows in moist clay soils amongst dense small plants in

wandoo Wandoo is the common name for a number of Western Australian ''Eucalyptus'' species, all of which have smooth white bark. The original "wandoo" is ''Eucalyptus wandoo''. Additional species have been given this name because of a perceived likeness w ...

woodland.

Conservation

''Caladenia dorrienii'' is classified as "endangered" under the Australian Government Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) and as "rare flora" under the Western Australian ''

Wildlife Conservation Act 1950 The ''Wildlife Conservation Act 1950'' is an act of the Western Australian Parliament that provides the statute relating to conservation and legal protection of flora and fauna. Text was copied from this source, which is available under Attrib ...

''.

References

{{Taxonbar, from=Q15287518 dorrienii Orchids of Western Australia Endemic orchids of Australia Plants described in 1912 Endemic flora of Western Australia