''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 (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

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. Orchids are cosmopolitan plants that are found in almost every habitat on Eart ...

family (Orchidaceae) and is

endemic Endemism is the state of a species being found only 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 foun ...

to south-eastern

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. 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 In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...

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 Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...

sympodial In botany, 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, als ...

herb Herbs are a widely distributed and widespread group of plants, excluding vegetables, with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal purposes, or for fragrances. Culinary use typically distingu ...

with an underground tuber which produces daughter tubers on the end of root-like

stolon In biology, a stolon ( from Latin ''wikt:stolo, stolō'', genitive ''stolōnis'' – "branch"), also known as a runner, is a horizontal connection between parts of an organism. It may be part of the organism, or of its skeleton. Typically, animal ...

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, associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves in size, color, shape or texture. They also lo ...

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 The fus ...

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 Etymology The term ''sepalum'' ...

and

petal Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corol ...

s are long about wide and the

lateral Lateral is a geometric term of location which may also refer to: Biology and healthcare * Lateral (anatomy), a term of location meaning "towards the side" * Lateral cricoarytenoid muscle, an intrinsic muscle of the larynx * Lateral release ( ...

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

ovary The ovary () is a gonad in the female reproductive system that produces ova; when released, an ovum travels through the fallopian tube/ oviduct into the uterus. There is an ovary on the left and the right side of the body. The ovaries are end ...

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

callus A callus (: calluses) 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, b ...

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

thorax The thorax (: thoraces or thoraxes) or chest is a part of the anatomy of 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 di ...

" 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, (; 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 Victoria, Australia ...

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 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 (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

(''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 In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

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 arrives at the Stigma (botany), stigma of a flower (in flowering plants) or at the ovule (in gymnosperms) of the same plant. The term cross-pollination is used for the opposite case, where ...

. 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 cult ...

'' 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 ...

''. 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 passerine songbird, one of two species from the family Menuridae, with the other being the much rarer Albert's lyrebird. It is one of the world's largest songbirds, and is re ...

(''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 New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

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. It runs roughl ...

south from the Blue Mountains and is widespread in eastern

Victoria Victoria most commonly refers to: * Queen Victoria (1819–1901), Queen of the United Kingdom and Empress of India * Victoria (state), a state of Australia * Victoria, British Columbia, Canada, a provincial capital * Victoria, Seychelles, the capi ...

. 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. Today Flinders Island is part of the state of Tasmania, Australia. It is from Cape Portland, Tasmania, Cape Portl ...

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

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 (state) Orchids of Tasmania Taxa named by Ferdinand von Mueller