Pterostylis australis
Common names
southern greenhood
Biostatus
Native
Category
Vascular
Structural class
Orchids
Flower colours
Green, White
Detailed description
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 × 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
Distribution
Endemic. New Zealand: North Island (present only from the the East Cape area south and becoming more common in the southern third of the island), South Island, Stewart Island/Rakiura.
Habitat
Lowland to subalpine (up to 1200 m a.s.l.) in scrub and tall forest. Generally preferring beech (Nothofagaceae)-dominated forest in the North Island and South Island. Mostly montane in the North Island. Sometimes found in forestry plantations.
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – these interim threat classification statuses has not been assessed by the NZTCS panel.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2023 | Not Threatened
Detailed taxonomy
Family
Orchidaceae
Synonyms
None
Taxonomic notes
On Stewart Island/Rakiura, especially, this species often has distinctly toothed to finely denticulate leaf margins.
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
November–January
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.
Other information
Etymology
pterostylis: Winged column
australis: Southern
Manaaki Whenua Online Interactive Key
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
Previous conservation statuses
2017 | Not Threatened
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Referencing and citations
References and further reading
Moore LB, Edgar E. 1970. Flora of New Zealand, Volume II. Indigenous Tracheophyta: Monocotyledones except Gramineae. Government Printer, Wellington, NZ. 354 p.
Attribution
Fact Sheet prepared for NZPCN by P.J. de Lange 14 April 2007: Description adapted from Moore and Edgar (1970).
Some of this factsheet information is derived from Flora of New Zealand Online and is used under a Creative Commons Attribution 3.0 New Zealand licence.
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)