''Caladenia radialis'', commonly known as the drooping spider orchid, is a species of orchid endemic to the

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of Western Australia. It has a single erect, hairy leaf and one or two red and cream-coloured flowers. In good seasons it forms clumps of up to ten plants. Caladenia radialis 01

Description

''Caladenia radialis'' is a terrestrial, perennial, deciduous,

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 often forms clumps of up to ten plants after good rainfall. It has a single erect, hairy leaf, long and about wide. One or two red and cream-coloured flowers long and wide are borne on a stalk tall. The 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 have long, brown, drooping thread-like tips. The dorsal sepal curves forward and is long and about wide. The lateral sepals and petals have about the same dimensions as the dorsal sepal although the lateral sepals are slightly wider. The labellum is long, wide and cream-coloured with red lines. The sides of the labellum sometimes have a few short teeth, the tip is curled under and there is a dense band of red or cream-coloured calli along the mid-line. Flowering occurs from August to early October.

Taxonomy and naming

''Caladenia radialis'' was first described in 1927 by

Richard Rogers Richard George Rogers, Baron Rogers of Riverside (23 July 1933 – 18 December 2021) was a British architect noted for his modernist and Functionalism (architecture), functionalist designs in high-tech architecture. He was a senior partner a ...

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

Transactions and Proceedings of the Royal Society of South Australia The Royal Society of South Australia (RSSA) is a learned society whose interest is in science, particularly, but not only, of South Australia. The major aim of the society is the promotion and diffusion of scientific knowledge, particularly in rel ...

''. 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 ...

(''radialis'') is derived from the Latin word ''radius'' meaning "ray", "rod" or "spoke", referring to the radiating red lines on the labellum.

Distribution and habitat

The drooping spider orchid is found between the Fitzgerald River National Park and

Northampton Northampton () is a market town and civil parish in the East Midlands of England, on the River Nene, north-west of London and south-east of Birmingham. The county town of Northamptonshire, Northampton is one of the largest towns in England; ...

in the Avon Wheatbelt, Esperance Plains, Geraldton Sandplains, Jarrah Forest 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 ...

where it grows in a range of habitats including on granite outcrops and near the edges of salt lakes.

Conservation

''Caladenia radialis'' 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=Q15287616 radialis Endemic orchids of Australia Orchids of Western Australia Plants described in 1927 Endemic flora of Western Australia