''Caladenia formosa'', commonly known as the large crimson spider orchid, or elegant spider orchid is a plant in the orchid family

Orchidaceae 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 ...

and is

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 Victoria and

South Australia South Australia (commonly abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territories ...

. It is a ground orchid with a single hairy leaf and a single crimson-coloured flower and which mainly occurs only in south-western Victoria.

Description

''Caladenia formosa'' 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 a single, reddish-green, hairy leaf, long and wide. One, sometimes two, pale red to crimson flowers across are borne on a hairy spike 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 taper to a long, thin tip which is densely covered with crowded

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 ...

and glandular hairs. The dorsal sepal is erect, long, wide and the lateral sepals are long and wide at the base. The petals are long, wide at the base. The labellum is long and wide with its edges turned up and its tip rolled under. It is pink to red and there are red teeth up to long along the edges and all the way to the tip of the labellum. There are four or six rows of long, red calli along the centre line of the labellum. Flowering occurs from September to October.

Taxonomy and naming

''Caladenia formosa'' was first formally described by

Geoffrey Carr Geoffrey Carr (22 January 1886 – 13 July 1969) was a Great Britain, British rowing Coxswain (rowing), coxswain who competed in the 1912 Summer Olympics. Carr was born in Putney and became a member of Thames Rowing Club. He was the coxswain ...

in 1991 from a specimen collected in the

Dergholm State Park The Dergholm State Park is located in the far west of Victoria, Australia. It is 390 km west of Melbourne and 450 km east of Adelaide, South Australia. Introduction The park has an area of 104 square kilometres and has a relatively dr ...

. The description was published in ''Indigenous Flora and Fauna Association Miscellaneous Paper 1''. 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 ...

(''formosa'') is a

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

word meaning “beautifully-formed” or "handsome".

Distribution and habitat

The large crimson spider orchid grows among shrubs or grass in forest and woodland in well-drained soil. It is only known from areas between Cavendish, Penola,

Kingston SE Kingston SE (Kingston South East to distinguish it from Kingston-on-Murray) formerly Kingston is a town in the Australian state of South Australia located in the state's south-east coastline on the shores of Lacepede Bay. It is located about ...

and

Keith Keith may refer to: People and fictional characters * Keith (given name), includes a list of people and fictional characters * Keith (surname) * Keith (singer), American singer James Keefer (born 1949) * Baron Keith, a line of Scottish barons ...

although it probably had a wider distribution in the past.

Conservation

''Caladenia formosa'' is listed as "vulnerable" under the Victorian Government ''

Flora and Fauna Guarantee Act 1988 The ''Flora and Fauna Guarantee Act 1988'', also known as the ''FFG Act'', is an act of the Victorian Government designed to protect species, genetic material and habitats, to prevent extinction and allow maximum genetic diversity within the Au ...

'' and the Australian Government '' Environment Protection and Biodiversity Conservation Act 1999''. In 2010 the population of this orchid was estimated to comprise 450 individual plants in fourteen populations. The main threats to the species are weed invasion and habitat loss or degradation due to land clearing, rubbish dumping and grazing by rabbits and cattle.

References

{{Taxonbar, from=Q9673609

formosa Taiwan, officially the Republic of China (ROC), is an island country located in East Asia. The main island of Taiwan, formerly known in the Western political circles, press and literature as Formosa, makes up 99% of the land area of the territorie ...

Plants described in 1991 Endemic orchids of Australia Orchids of Victoria (state)