Pterostylis australis
Common name
southern greenhood
Synonyms
None
Family
Orchidaceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Orchids
NVS code
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
PTEAUS
Chromosome number
2n = 44
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley.
2012 | Not Threatened
Previous conservation statuses
2009 | Not Threatened
2004 | Not Threatened
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.
Etymology
pterostylis: Winged column
australis: Southern
Where To Buy
Not commercially available
Taxonomy
On Stewart Island especially this species often has distinctly toothed to finely denticulate leaf margins.
Attribution
Fact Sheet prepared for NZPCN by P.J. de Lange 14 April 2007: Description adapted from Moore and Edgar (1970).
References and further reading
Moore, L.B.; Edgar, E. 1970: Flora of New Zealand. Vol. II. Government Printer, Wellington.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Pterostylis australis Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/pterostylis-australis/ (Date website was queried)