''Caladenia polychroma'', commonly known as the Joseph's 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 ...

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 erect, hairy leaf and one or two relatively large and colourful but smelly flowers. Caladenia polychroma 03

Description

''Caladenia polychroma'' 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 Tubers are a type of enlarged structure used as storage organs for nutrients in some plants. They are used for the plant's perennation (survival of the winter or dry months), to provide energy and nutrients for regrowth during the next growing ...

and which often grows in clumps. It has a single erect, hairy leaf, long and about wide. One or two creamy variably red, pink, yellow and white flowers long and wide are borne on a stalk tall. The

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 have long, thin, drooping, thread-like ends. The dorsal sepal is erect, long and wide. The lateral sepals are long and wide and curve stiffly downwards. The petals are long, wide and arranged like the lateral sepals. The labellum is long, wide and cream-coloured to yellow with red lines, spots and blotches. The sides of the labellum have short, blunt teeth and the tip is curled under. There are two rows of anvil-shaped, cream-coloured calli along the mid-line of the labellum. Flowering occurs from September to October.

Taxonomy and naming

''Caladenia polychroma'' was first described in 2001 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 Phillip Brown Andrew Phillip Brown (born 1951) is a conservation biologist and taxonomist at the Western Australian Department of Environment and Conservation. He is also curator of Orchidaceae and Myoporaceae Myoporaceae was a family of plants, found mostly ...

from a specimen collected near Kendenup and the description was published in ''

Nuytsia ''Nuytsia floribunda'' is a hemiparasitic tree found in Western Australia. The species is known locally as moodjar and, more recently, the Christmas tree or Western Australian Christmas tree. The display of intensely bright flowers during the ...

''. 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 ...

(''polychroma'') is derived from the

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...

words ''poly'' meaning "many" and ''chroma'' meaning "colour" referring to the colouring of the flowers.

Distribution and habitat

Joseph's spider orchid occurs between Frankland and the Fitzgerald River National Park in the Avon Wheatbelt,

Esperance Plains Esperance Plains, also known as Eyre Botanical District, is a biogeographic region in southern Western Australia on the south coast between the Avon Wheatbelt and Hampton bioregions, and bordered to the north by the Mallee region. It is a pl ...

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 ...

and Mallee

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 ...

but is most common between Cranbrook and Kojonup. It grows near seasonally wet areas and drainage lines.

Conservation

''Caladenia polychroma'' is classified as "not threatened" 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 ...

References

{{Taxonbar, from=Q15287647 polychroma Endemic orchids of Australia Orchids of Western Australia Plants described in 2001 Endemic flora of Western Australia Taxa named by Stephen Hopper Taxa named by Andrew Phillip Brown