''Pterostylis falcata'', commonly known as the sickle greenhood, is a species of orchid 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 bright green leaves at the base of the plant and a single green and white, sickle-shaped flower. It is widespread and often common in Victoria but also occurs further north and west, and in Tasmania

Description

''Pterostylis falcata'' 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 and a rosette of three to six bright green leaves surrounding the base of the flowering stem. Each leaf is lance-shaped to egg-shaped, long and wide. A single dark green and white flower long and wide is borne on a spike high. 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 fused, forming a hood or "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. ...

. The dorsal sepal is much longer than the petals and gradually tapers to a point. There is a wide gap between the galea and the lateral sepals. The lateral sepals are erect and have narrow tips long and a deep V-shaped sinus between them. The labellum is long, wide, brown and curved and half of it protrudes through the sinus. Flowering occurs from September to February.

Taxonomy and naming

''Pterostylis falcata'' was first formally described in 1915 by Richard Sanders Rogers and the description was published in '' Proceedings of the Royal Society of Victoria''. 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 ...

(''falcata'') is a Latin word meaning "curved like a sickle".

Distribution and habitat

The sickle greenhood occurs in the south-eastern states of Australia where it grows in wet places such as near creeks and the rosette is sometimes covered by flowing water. It is most common and widespread in Victoria but is also found in eastern New South Wales, the Australian Capital Territory, Queensland, South Australia and Tasmania but is classed as "endangered" in the last two of these states.

References

{{Taxonbar, from=Q29650689 falcata Endemic orchids of Australia Orchids of the Australian Capital Territory Orchids of New South Wales Orchids of Queensland Orchids of South Australia Orchids of Tasmania Orchids of Victoria (Australia) Plants described in 1915