''Arthrochilus huntianus'', commonly known as common elbow orchid, is a

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

in the

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 ...

family (Orchidaceae) 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 south-eastern

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. It has no leaves but an insect-like flower which has its labellum dangling like a lure away from the rest of the flower. Because of its thin, wiry stem and small, dull-coloured flowers, this orchid is difficult to locate. Like others in the genus, the flowers are pollinated by a species of thynnid wasp. Some authorities use the name ''Thynninorchis huntiana'' for this orchid.

Description

''Arthrochilus huntianus'' is a leafless 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 ...

sympodial Sympodial growth is a bifurcating branching pattern where one branch develops more strongly than the other, resulting in the stronger branches forming the primary shoot and the weaker branches appearing laterally. A sympodium, also referred to a ...

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 which produces daughter tubers on the end of root-like

stolon In biology, stolons (from Latin '' stolō'', genitive ''stolōnis'' – "branch"), also known as runners, are horizontal connections between organisms. They may be part of the organism, or of its skeleton; typically, animal stolons are external s ...

s. Up to ten insect-like flowers long and about wide are borne on a thin, wiry, green to reddish flowering stem tall. There are two, three or four

bract In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves. They may be smaller, larger, or of ...

s at the base of the flowering stem. The

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal co ...

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 ...

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 long about wide and the

lateral Lateral is a geometric term of location which may refer to: Healthcare *Lateral (anatomy), an anatomical direction *Lateral cricoarytenoid muscle *Lateral release (surgery), a surgical procedure on the side of a kneecap Phonetics *Lateral cons ...

sepals are long and about wide. The sepals and petals all turn downwards towards 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. ...

. The labellum is long about wide on a thin stalk or "claw" long. The labellum

callus A callus is an area of thickened and sometimes hardened skin that forms as a response to repeated friction, pressure, or other irritation. Since repeated contact is required, calluses are most often found on the feet and hands, but they may o ...

is insect-like and consists of a shiny black "head" with two

antenna Antenna ( antennas or antennae) may refer to: Science and engineering * Antenna (radio), also known as an aerial, a transducer designed to transmit or receive electromagnetic (e.g., TV or radio) waves * Antennae Galaxies, the name of two collid ...

-like structures, a "

thorax The thorax or chest is a part of the anatomy of humans, mammals, and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main divisions of the cre ...

" with long purplish or reddish hairs and a pair of long branched tails with tiny bristles. There are two pairs of curved wings on the

column A column or pillar in architecture and structural engineering is a structural element that transmits, through compression, the weight of the structure above to other structural elements below. In other words, a column is a compression member. ...

. Flowering occurs from November to March.

Taxonomy and naming

The common elbow orchid was first formally described in 1889 by

Ferdinand von Mueller Baron Sir Ferdinand Jacob Heinrich von Mueller, (german: Müller; 30 June 1825 – 10 October 1896) was a German-Australian physician, geographer, and most notably, a botanist. He was appointed government botanist for the then colony of Vict ...

and given the name ''Drakaea huntiana''. The description was published in ''

The Victorian Naturalist ''The Victorian Naturalist'' is a bimonthly scientific journal covering natural history, especially of Australia. It is published by the Field Naturalists Club of Victoria and is received as part of the membership subscription of that club. From ...

'' from a specimen collected "between loose stones on Mount Tingiringi". In 1972

Donald Blaxell Donald Frederick Blaxell (born 1 February 1934, Sydney, New South Wales), is an Australian botanist, botanical collector and taxonomist. Blaxell worked at the University of New South Wales for 11 years and joined the New south Wales Herbarium in ...

changed the name to ''Arthrochilus huntianus'' and in 2002 David Jones and Mark Clements changed the name to ''Thynninorchis huntiana'' but the latter name has not been universally accepted. 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 ...

(''huntianus'') honours "Robt. Hunt, Esq. C.M.G., F.G.S., Master of the Sydney-Mint and Vice-President of the Committee of the Technological Museum" who discovered this species. In 1998 David Jones described two subspecies of ''A. huntianus'': * ''Arthrochilus huntianus'' subsp. ''huntianus'' which occurs on continental Australia and formerly on Flinders Island; * ''Arthrochilus huntianus'' subsp. ''nothofagicola'' which grows in dense rainforest with ''

Nothofagus cunninghamii ''Nothofagus cunninghamii,'' commonly known as myrtle beech or Tasmanian myrtle, is the dominant species of cool temperate rainforests in Tasmania and Southern Victoria. It has low fire resistance and grows best in partial shade conditions. It ...

'' which has a smaller labellum callus and is probably

self-pollinating Self-pollination is a form of pollination in which pollen from the same plant arrives at the stigma of a flower (in flowering plants) or at the ovule (in gymnosperms). There are two types of self-pollination: in autogamy, pollen is transferred to ...

. In 2002 David Jones and Mark Clements raised the subspecies ''nothofagicola'' to species status as ''Thynninorchis nothofagicola'' but the name has not been accepted by some authorities. The two subspecies of ''Arthrochilus huntianus'' differ from other orchids in the genus by being leafless and having the labellum dangling with an insect-like "lure" on the end. ''Arthrochilus huntianus'' subsp. ''nothofagicola'', as ''Thynninorchis nothofagicola'', is classified as "critically endangered" under the Australian Government ''

Environment Protection and Biodiversity Conservation Act 1999 The ''Environment Protection and Biodiversity Conservation Act 1999'' (Cth) is an Act of the Parliament of Australia that provides a framework for protection of the Australian environment, including its biodiversity and its natural and cultu ...

'' and as "endangered" under the Tasmanian ''

Threatened Species Protection Act 1995 The ''Threatened Species Protection Act 1995'' (TSP Act), is an act of the Parliament of Tasmania that provides the statute relating to conservation of flora and fauna. Its long title is An Act to provide for the protection and management of th ...

''. The species (or subspecies) is only known from a single site and is threatened by the activities of the introduced

superb lyrebird The superb lyrebird (''Menura novaehollandiae'') is an Australian songbird, one of two species from the family Menuridae. It is one of the world's largest songbirds, and is renowned for its elaborate tail and courtship displays, and its excell ...

(''Menura novaehollandiae''), by fire, forestry activities and climate change.

Distribution and habitat

''Arthrochilus huntianus'' grows in woodland and forest, usually in leaf litter. In

New South Wales ) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , es ...

it mainly grows on the

Great Dividing Range The Great Dividing Range, also known as the East Australian Cordillera or the Eastern Highlands, is a cordillera system in eastern Australia consisting of an expansive collection of mountain ranges, plateaus and rolling hills, that runs rough ...

south from the Blue Mountains and is widespread in eastern

Victoria Victoria most commonly refers to: * Victoria (Australia), a state of the Commonwealth of Australia * Victoria, British Columbia, provincial capital of British Columbia, Canada * Victoria (mythology), Roman goddess of Victory * Victoria, Seychelle ...

. It formerly occurred on

Flinders Island Flinders Island, the largest island in the Furneaux Group, is a island in the Bass Strait, northeast of the island of Tasmania. Flinders Island was the place where the last remnants of aboriginal Tasmanian population were exiled by the colon ...

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

but is now regarded as extinct there.

Ecology

As with other ''Arthrochilus'' orchids, ''A. huntianus'' is pollinated by males thynnid wasps of the genus '' Arthrothynnus'' although the species involved is not known. It also reproduces asexually by producing new tubers.

References

{{Taxonbar, from1=Q15491916, from2=Q27865606, from3=Q27828814 huntianus Plants described in 1991 Orchids of the Australian Capital Territory Orchids of New South Wales Orchids of Victoria (Australia) Orchids of Tasmania Taxa named by Ferdinand von Mueller