''Prasophyllum petilum'', commonly known as the Tarengo leek 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 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 a single tubular, green leaf and up to eighteen pinkish mauve to greenish flowers, well-spaced along a slender flowering stem. It is a small orchid, difficult to locate, generally growing in taller grasses. Prasophyllum petilum (habit)

Description

''Prasophyllum petilum'' 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 tube-shaped, dark green leaf. The leaf has a purplish base and is long and wide. Between five and eighteen, sometimes fragrant flowers are crowded along a flowering spike about long. The flowers are pinkish mauve to greenish and wide. As with others in the genus, the flowers are inverted so that the labellum is above 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. ...

rather than below it. 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 ...

is a narrow egg-shape to lance-shape, long and about wide. 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 about the same length as the dorsal sepal but narrower and joined to each other for about half their length. The

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 linear to lance-shaped and about long. The labellum is linear to egg-shaped, long, turns upwards and has slightly wavy edges. There is a fleshy, yellowish-green

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 ...

in the centre of the labellum. Flowering occurs in late October and November.

Taxonomy and naming

''Prasophyllum petilum'' was first formally described in 1991 by David Jones and Robert Bates from a specimen collected at Hall Cemetery in the

Australian Capital Territory The Australian Capital Territory (commonly abbreviated as ACT), known as the Federal Capital Territory (FCT) until 1938, is a landlocked federal territory of Australia containing the national capital Canberra and some surrounding townships. ...

and the description was published in ''Australian Orchid Research''. 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 ...

(''petilum'') 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 "slender" or "thin", referring the habit of this species.

Distribution and habitat

The Tarengo leek orchid grows in grassland and grassy woodland, often growing in colonies when not subject to grazing. It has been recorded at

Hall In architecture, a hall is a relatively large space enclosed by a roof and walls. In the Iron Age and early Middle Ages in northern Europe, a mead hall was where a lord and his retainers ate and also slept. Later in the Middle Ages, the gr ...

Boorowa Boorowa () is a farming village in the Hilltops Council, Hilltops Region in the South West Slopes, south west slopes of New South Wales, Australia. It is located in a valley southwest of Sydney around above sea-level. The town is in Hilltop ...

, Ilford,

Delegate Delegate or delegates may refer to: * Delegate, New South Wales, a town in Australia * Delegate (CLI), a computer programming technique * Delegate (American politics), a representative in any of various political organizations * Delegate (United ...

, near

Queanbeyan Queanbeyan ( ) is a city in the south-eastern region of New South Wales, Australia, located adjacent to the Australian Capital Territory in the Southern Tablelands region. Located on the Queanbeyan River, the city is the council seat of the ...

and

Muswellbrook Muswellbrook ( ) is a town in the Upper Hunter Region of New South Wales, Australia, about north of Sydney and north-west of Newcastle. Geologically, Muswellbrook is situated in the northern parts of the Sydney basin, bordering the New Englan ...

Conservation

''Prasophyllum petilum'' is classified as ''Endangered'' under the New South Wales ''Threatened Species Conservation Act'' and the Commonwealth 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 ...

'' (EPBC) Act.

References

External links

* * {{Taxonbar, from=Q15491248 petilum Flora of the Australian Capital Territory Flora of New South Wales Endemic orchids of Australia Plants described in 1991