''Prasophyllum pallidum'', commonly known as the pale 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 a south-eastern

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 has a single tubular leaf and up to thirty green or yellowish-green flowers. It was previously thought to occur in Victoria but records from that state are now recognised as '' P. roseum''.

Description

''Prasophyllum pallidum'' 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 leaf long and wide. Between fifteen and thirty five flowers are well-spaced along a flowering stem long which reaches to a height of . The flowers are green or yellowish-green and as with others in the genus, 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

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. ...

is swollen, realively large compared to the rest of the flower and stands out from the flowering stem. The dorsal

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 lance-shaped to egg-shaped, long, about wide and slightly dished. The lateral sepals are a similar length to the dorsal sepal but narrower and are free from each other. 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 long, about wide and curve forwards. The labellum is wedge-shaped to egg-shaped, about long and wide and turns sharply upwards near its middle. The edges of the labellum are crinkled and there is a pale green, fleshy callus along the centre of the labellum, extending almost to its tip. Flowering occurs from September to November and is stimulated by earlier fires.

Taxonomy and naming

''Prasophyllum pallidum'' was first formally described in 1930 by

William Henry Nicholls William Henry Nicholls (23 July 1885 – 10 March 1951) was an Australian amateur botanist, authority on, and collector of Australian orchids. An accomplished photographer and watercolourist, he contributed almost 100 articles on orchids to ''The ...

and 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 near

Pomonal Pomonal is a town in western Victoria, Australia within the Rural City of Ararat local government area, north west of the state capital, Melbourne. At the , Pomonal had a population of 356. History Reflecting the many orchards in the area ...

. 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 ...

(''pallidum'') 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 "ashen", "pale" or "wan". Specimens collected in Victoria as ''P. pallidum'' are now included in '' P. roseum''.

Distribution and habitat

The pale leek orchid mostly grows in grassy forest from the Flinders Ranges to the

Mount Lofty Ranges The Mount Lofty Ranges are a range of mountains in the Australian state of South Australia which for a small part of its length borders the east of Adelaide. The part of the range in the vicinity of Adelaide is called the Adelaide Hills and ...

Conservation

''Prasophyllum pallidum'' is listed "Vulnerable" under the Commonwealth Government '' Environment Protection and Biodiversity Conservation Act 1999'' (EPBC) Act and under the South Australian'' National Parks and Wildlife Act 1972''.

References

External links

* {{Taxonbar, from=Q15489653 pallidum Flora of South Australia Endemic orchids of Australia Plants described in 1930