''Pterostylis aciculiformis'', commonly known as the needle-point rustyhood or slender ruddyhood, 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 ten green and brown flowers with a brown, insect-like labellum. It is widespread and locally common in New South Wales and Victoria, growing mostly in drier forests.

Description

''Pterostylis aciculiformis'', 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 leaves at the base of the flowering spike, each leaf long and wide. Up to twelve green and brown flowers long and wide are borne on a flowering spike tall. Three to six stem leaves are wrapped 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 over the column with the dorsal sepal having an upturned point about long. The lateral sepals turn downwards, curve forwards and are narrower than the hood. They have thread-like tips long and are more or less parallel to each other. The labellum is brown, fleshy and insect-like, about long and wide. The "head" end is swollen, there are 6 to 12 white bristles on each side and many short bristles on the "tail" end. Flowering occurs from September to December.

Taxonomy and naming

The needle-point rustyhood was first formally described in 1936 by William Nicholls who gave it the name ''Pterostylis pusilla'' var. ''aciculiformis'' and published the description 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 ...

''. In 1989, Mark Clements and David Jones raised it to species status. 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 ...

(''aciculiformis'') is derived from the Latin word ''acicula'' meaning "a small pin" and the

suffix In linguistics, a suffix is an affix which is placed after the stem of a word. Common examples are case endings, which indicate the grammatical case of nouns, adjectives, and verb endings, which form the conjugation of verbs. Suffixes can carry ...

''-formis''.

Distribution and habitat

''Pterostylis aciculiformis'' occurs in disjunct populations south from Wellington in New South Wales and across northern Victoria, growing mostly in drier forests in stony soils. It may also occur in far eastern South Australia.

References

{{Taxonbar, from=Q15491316 aciculiformis Endemic orchids of Australia Orchids of New South Wales Orchids of Victoria (Australia) Plants described in 1936