''Pterostylis cucullata'', commonly known as the leafy greenhood, is a plant in the orchid family Orchidaceae and is endemic 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 a rosette of fleshy leaves at its base and a single white, green and reddish-brown flower.

Description

''Pterostylis cucullata'', is a terrestrial, perennial, deciduous,

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. It has between four and seven egg-shaped to oblong leaves, some of which form a rosette at the base and some partly wrap around the flowering stem. The leaves are long and wide, dark green, fleshy and flat. A single white, green and reddish-brown flower is borne on a flowering stem high. The flowers are long, wide. The dorsal sepal 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 joined and curve forward in a semi-circle, forming a hood called the "galea" over 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. ...

. There is a wide gap at each side of the flower between the petals and the lateral sepals. The lateral sepals have a tapering tip, long, only slightly longer than the galea and there is a narrow but deep notch in the sinus between them. The labellum is long, about wide, slightly curved, dark brown and blunt and only protrudes slightly above the sinus. Flowering occurs from August to October.

Taxonomy and naming

''Pterostylis cucullata'' was first formally described in 1810 by Robert Brown and the description was published in '' Prodromus Florae Novae Hollandiae et Insulae Van Diemen''. 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 ...

(''cucullata'') is derived from the Latin word ''cucullus'' meaning "cap", or "hood". There are two subspecies, differing mainly in the height of the flowering stem: * ''Pterostylis cucullata'' subsp. ''cucullata'' grows to a height of ; * ''Pterostylis cucullata'' subsp. ''sylvicola'' grows to a height of up to .

Distribution and habitat

The leafy greenhood is widely distributed in Victoria, South Australia and Tasmania but only in small, isolated populations. Both subspecies are present in Victoria as small groups in coastal areas and inland watercourses. It grows in shady forest slopes in South Australia but is very rare there. It is extinct on the main island of Tasmania and

King Island King Island, Kings Island or King's Island may refer to: Australia * King Island (Queensland) * King Island, at Wellington Point, Queensland * King Island (Tasmania) ** King Island Council, the local government area that contains the Tasmanian is ...

, presently found only on Hunter Island and Three Hummock Island in

Bass Strait Bass Strait () is a strait separating the island state of Tasmania from the Australian mainland (more specifically the coast of Victoria, with the exception of the land border across Boundary Islet). The strait provides the most direct waterwa ...

Conservation

''Pterostylis cucullata'' is listed as "vulnerable" under the Australian Government '' Environment Protection and Biodiversity Conservation Act 1999''. The main threats to the species are habitat loss and disturbance, weed invasion and grazing by rabbits, hares and snails.

References

{{Taxonbar, from=Q15495092 cucullata Endemic orchids of Australia Orchids of South Australia Orchids of Tasmania Orchids of Victoria (Australia) Plants described in 1810