''Pterostylis crassicaulis'', commonly known as the alpine swan 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 leaves and up to 18 bluish-green and white flowers with dark green stripes. The flowers have a labellum with a dark green, beak-like

appendage An appendage (or outgrowth) is an external body part, or natural prolongation, that protrudes from an organism's body. In arthropods, an appendage refers to any of the homologous body parts that may extend from a body segment, including anten ...

. It is similar to ''P. cycnocephala'' but is more robust and grows at higher altitudes.

Description

''Pterostylis crassicaulis'', 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 a rosette of between five and eight crowded, dark green leaves at the base of the flowering spike, each leaf long and wide. Between 5 and 18 shiny bluish-green and white flowers with dark green lines and long are borne on a flowering spike up to tall. Four to six stem leaves are wrapped loosely around the flowering spike. 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 form a hood or "galea" over the column. The dorsal sepal is curved forwards with the sides turned down. The lateral sepals turn downwards, are long and wide, dished and joined near their bases. The labellum is oblong to egg-shaped, about long and wide, pale green with a dark green, beak-like appendage pointing forward at its base. Flowering occurs from December to January.

Taxonomy and naming

The alpine swan greenhood was first formally described in 2008 by David Jones and Mark Clements and given the name ''Hymenochilus crassicaulis''. The description was published in ''The Orchadian'' from a specimen collected in the

Kosciuszko National Park The Kosciuszko National Park () is a national park and contains mainland Australia's highest peak, Mount Kosciuszko, for which it is named, and Cabramurra, the highest town in Australia. Its borders contain a mix of rugged mountains and wildern ...

. In 2010,

Gary Backhouse Gary may refer to: *Gary (given name), a common masculine given name, including a list of people and fictional characters with the name *Gary, Indiana, the largest city named Gary Places ;Iran * Gary, Iran, Sistan and Baluchestan Province ;Uni ...

changed the name to ''Pterostylis crassicaulis'', publishing the change 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 ...

''. 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 ...

(''crassicaulis'') is derived from the Latin words ''crassus'' meaning "thick", "fat" or "stout" and ''caulis'' meaning "stalk" or "stem".

Distribution and habitat

The alpine swan greenhood grows in alpine and subalpine grasslands and herbfields in eastern Victoria and on the Southern Tablelands of New South Wales.

References

{{Taxonbar, from=Q17329299 crassicaulis Endemic orchids of Australia Orchids of New South Wales Orchids of Victoria (Australia) Plants described in 2008