''Pterostylis mutica'', commonly known as the midget greenhood, is a plant in the orchid family Orchidaceae and is endemic to

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 ...

, occurring in all states but not the Northern Territory. There is a rosette of leaves at the base of the flowering stem and up to fifteen pale green flowers which have a sensitive labellum. Pterostylis mutica (labelled)

Description

''Pterostylis mutica'', 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. There is a rosette of between six and twelve, egg-shaped leaves, each leaf long and wide at the base of the plant. Between two and twenty well-spaced flowers are borne on a flowering spike high with five to ten stem leaves wrapped around it. The flowers are pale green, long and about 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 to form a hood called the "galea" over the column. The galea is curved with a pointed tip turning downwards. The lateral sepals turn downwards and are about long, wide, cupped and joined for most of their length. The labellum is about long, about wide and whitish-green with a dark green

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 ...

. Flowering occurs from July to December.

Taxonomy and naming

''Pterostylis mutica'' was first formally described in 1810 by Robert Brown from a specimen collected near Port Jackson 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 ...

(''mutica'') is a Latin word meaning "shortened" or "docked" referring to the blunt petals and sepals.

Distribution and habitat

''Pterostylis mutica'' is widespread and often common, growing in a wide range of habitats from near the coast to mountains, but usually in well-drained soil. It tolerates dry conditions, poor soil and exposed positions. It is widespread in New South Wales and Victoria and also occurs in south-east Queensland, south-eastern South Australia and the south-west of Western Australia. There is doubt about its presence in Tasmania

Ecology

The labellum of ''P. mutica'' is attractive to a species of gnat which lands on the labellum and grasps the dark green appendage. When it does so, the labellum springs upward, trapping the insect inside the now-closed flower. The gnat can now only escape by pushing between "wings" on the sides of 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. ...

. As it does so, it either removes a pollinium or deposits one from a previously-visited flower of the same species, and pollination occurs.

References

{{Taxonbar, from=Q15497032 mutica Endemic orchids of Australia Orchids of New South Wales Orchids of Queensland Orchids of South Australia Orchids of Tasmania Orchids of Victoria (Australia) Plants described in 1810