''Pterostylis oliveri'' is a species of greenhood orchid endemic to New Zealand. Flowering have plants spreading leaves on the flowering stem and a single green and white flower with a strongly down-curved dorsal sepal and long, tapering lateral sepals.

Description

''Pterostylis oliveri'' 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. Flowering plants have between three and five spreading leaves which are long and wide, grading from narrow egg-shaped near the base to lance-shaped near the top. There is a single green and white flower on a flowering stem 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 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 tall and curves forward then strongly downward with a long, tapering tip which is much longer than the

s. There is a gap between the galea and the lateral sepals which have long, tapering tips, spread apart from each other and are erect or turned back behind the galea. The labellum is gently curved and protrudes above the sinus between the lateral sepals. Flowering occurs in December and January.

Taxonomy and naming

''Pterostylis oliveri'' was first formally described by Donald Petrie and the description was published in '' Transactions and Proceedings of the New Zealand Institute'' in 1894. 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 ...

(''oliveri'') honours Professor Daniel Oliver of Kew Gardens for his assistance to Petrie.

Distribution and habitat

Oliver's greenhood grows in forest and scrub, often on the side of streams or in dense leaf litter on the

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...

from near Nelson to Arthurs Pass National Park.

Conservation

''Pterostylis oliveri'' is classed as "not threatened".

References

{{Taxonbar, from=Q15500253

oliveri Oliveri ( Sicilian: ''Oluveri'') is a ''comune'' (municipality) in the Province of Messina in the Italian region Sicily, located about east of Palermo and about west of Messina. As of 31 December 2004, it had a population of 2,076 and an are ...

Plants described in 1894 Endemic orchids of New Zealand