''Pterostylis mirabilis'', commonly known as the nodding rufous-hood, is a plant in the orchid family Orchidaceae and is endemic to South Australia. It has a rosette of leaves at its base and up to ten greenish-white flowers with a narrow hood, down-turned lateral sepals and a thin-textured, insect-like labellum.

Description

''Pterostylis mirabilis'', 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 twelve egg-shaped, overlapping leaves which are about long and wide. Flowering plants have a rosette at the base of the flowering spike but the leaves are usually withered by flowering time. Up to ten greenish-white flowers which lean forward on a separate stalk are borne on a flowering stem up to tall. 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 with the dorsal sepal having a narrow tip long. The lateral sepals are narrow and turn downwards and suddenly narrow to thread-like tips up to long. The labellum is thinly-textured, green to pale brown and insect-like, about long with two hairs about long on the "head" end and eight to eleven shorter ones on each side of the "body".

Taxonomy and naming

This orchid was first formally described in 2007 by David Jones and given the name ''Oligochaetochilus mirabilis'' from a specimen collected near the road from Cowell to Kimba. The description was published in ''The Orchadian''. In 2008, Robert Bates changed the name to ''Pterostylis mirabilis''. 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 ...

(''mirabilis'') is a Latin word meaning "wonderful" or "strange".

Distribution and habitat

The nodding rufous-hood grows in rocky, hilly places, often under '' Melaleuca uncinata'' scrub. It is only known from about twelve locations on the Eyre Peninsula.

Conservation

''Pterostylis mirabilis'' is listed as "vulnerable" under the Australian Government '' Environment Protection and Biodiversity Conservation Act 1999''. The main threats to the species are habitat fragmentation, weed invasion, inappropriate fire regimes and agricultural practices.

References

{{Taxonbar, from=Q15493413 mirabilis Endemic orchids of Australia Orchids of South Australia Plants described in 1810