The New Zealand Plant Conservation Network

Species

Pterostylis australis

Etymology

Pterostylis: winged column
australis: southern

Common Name(s)

Southern Greenhood

Current Conservation Status

2012 - Not Threatened

Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB

Previous Conservation Status

2009 - Not Threatened
2004 - Not Threatened

Authority

Pterostylis australis Hook.f.

Family

Orchidaceae

Flora Category

Vascular - Native

NVS Species Code

PTEAUS

Structural Class

Orchids

Synonyms

None

Distribution

Endemic. North, South and Stewart Islands. In the North Island present only from the the East Cape area south and becoming more common in the southern third of the island.

Habitat

Lowland to subalpine (up to 1200 m a.s.l.) in scrub and tall forest. Generally preferring beech (Nothofagus Blume) dominated forest in the North and South Islands. Mostly montane in the North Island. Sometimes found in forestry plantations.

Features

Terrestrial, tuberous, glabrous, spring to summer-green perennial herb forming large colonies through vegetative extension. Plant at flowering 100-250 mm tall. Stem erect, smooth, dark green to reddish green, internodes < leaves. Leaves 4-5, shape changing from base to top of stem; lamina 40-150 x 10-16 mm, dark green to yellow-green, the lowest and those of non-flowering plants, elliptic to broadly elliptic, apex subacute, base subsessile or with a reddish-green winged petiole, margins entire or sometimes finely toothed; mid-stem and upper leaves longer and slightly narrower, more tapered, rarely narrowly lanceolate, margins entire or finely denticulate, 1, 2 or none of the leaves overtopping the flower. Flower solitary, large, dark green to pale green striped with white. Ovary erect. Dorsal sepal 25-45 mm tall, often rather smoothly arcuate but sometimes erect below then sharply horizontal above, apex acuminate often shortly caudate; lateral sepals diverging at a narrow angle, apices strongly reflexed backwards, spreading. Petals shorter than dorsal sepal, acute or acuminate. Labellum basally dark green flushed red or red from mid-section to apex, apex distinctly darker; lamina lanceolate-oblong, slightly arched, broadened almost to middle then narrowing to an obtuse, more or less deflexed, and decurved, pinched tip. Column as tall as labellum; stigma linear, often as broad as column, sometimes overlapped by wings from above.

Similar Taxa

Allied to Pterostylis banksii A.Cunn., and sometimes regarded as a form of it. Also close to P. areolata Petrie. It differs from P. banksii by the shorter, broader leaves, much shorter dorsal sepal and consistently arched labellum. From P. areolata it differs by the gradation from the elliptic (rarely broadly elliptic) basal leaves to almost linear-lanceolate mid-stem leaves; usually obviously caudate lateral sepals, and linear stigma

Flowering

November - January

Flower Colours

Green,White

Fruiting

January - April

Propagation Technique

Difficult - should not be removed from the wild. Basic orchid mix consists of 2 parts medium coarse sand, ideally clean river sand; 2 parts soil, humus or leaf-mould; 1 part weathered sawdust or rotting wood; 1 part granulated bark. For Pterostylis shade of 50% and pots kept evenly moist.

Threats

Not Threatened

Chromosome No.

2n = 44

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 31 Oct 2014