Species

Pterostylis alveata

Etymology

Pterostylis: winged column

Common Name(s)

Mountain Green Hood

Current Conservation Status

2012 - Non Resident Native - Coloniser

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 - Non Resident Native - Coloniser
2004 - Non Resident Native - Coloniser

Qualifiers

2012 - SO
2009 - SO

Authority

Pterostylis alveata Garnet

Family

Orchidaceae

Flora Category

Vascular - Native

NVS Species Code

DIPALV

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.

Structural Class

Orchids

Synonyms

Diplodium alveatum (Garnet) D.L.Jones et M.A.Clem.

Distribution

Indigenous. North and South Island, northern North West Nelson area. In February 2006 it was recorded at one site in the Hutt Valley. Present in Australia.

Habitat

Known in New Zealand from open kanuka (Kunzea ericoides (A.Rich.) Joy Thomps. shrubland where it grows on clay and sandy soils.

Features

Terrestrial orchid of open sites on clay or sand. Flowering plants up to 300 mm tall. Stem scabrid. Rosette leaves 3-5, 20-60 x 10-15 mm, ovate, elliptic to obovate, often rather distantly spaced on basal portion of stem, sessile, margins entire. Upper stem leaves rather bractaete, lanceolate, erect, and strongly stem clasping. Flower 30 mm long, erect, dark green striped white, apex of galea flat or slightly decurved; dorsal sepal acute to subacute, with a long, fine apiculus; lateral sepals erect, loosely embracing galea leaving a distinct lateral gap, sinus broadly notched when veiwed from the front, protruding prominently in an abrupt curve when viewed from the side, free points 20 mm long, linear-tapered, reflexed behind galea; petals broad, subacute. Labellum 13-18 x 3 mm, narrowly ovate-lanceolate to obtuse, dark brown, erect, curved forwards near middle, subacute with distal third projecting from the sinus in the set position.

Similar Taxa

Vegetative plants have some similarity to Diplodium alobulum (Hatch) D.L.Jones, Molloy et M.A.Clem., but the rosette leaves are much larger and more distantly spaced, further the stem is distinctly - though finely- scabrid. The stem leaves of D. alveatum are also distinctly narrowly-lanceolate, bract-like and closely stem clasping rather than broadly lanceolate, and patent to recurved as is typical of D. alobulum. The flowers of D. alveatum are much greener than the New Zealand Diplodia, the dorsal sepal has a long, wire like apiculus which often completely obscures the erect, dark brown, narrowly ovate-lacneolate to obtuse labellum.

Flowering

January - April

Flower Colours

Green,White

Fruiting

March - June

Propagation Technique

Difficult. Should not be removed from the wild

Threats

Possibly the target of orchid collectors. However only recently (late 1990s) discovered in New Zealand and still poorly known. A recent (2006) find in Wellington suggests that either this species has been overlooked or it is still expanding its range. Not serious threats are known.

Endemic Taxon

No

Endemic Genus

No

Endemic Family

No

Life Cycle and Dispersal

Minute seeds are wind dispersed (Thorsen et al., 2009).

Where To Buy

Not commercially available.

TAXONOMIC NOTES

Jane et al. (2010) following a thorough rDNA (ITS) based analysis of the segregate genera erected for Pterostylis R.Br. by Szlachekto (2001) and Jones et al. (2002) found no support to continue their recognition. This view, in the process of being adopted by the Australian Plants Names Index, is followed here.

 

Attribution

Fact Prepared for NZPCN by P.J. de Lange (17 April 2007). Description adapted from Moore and Edgar (1970)

References and further reading

Janes, J.K.; Dorothy A. S.; Vaillancourt, R.E.; Duretto, M.F. 2010: A new classification for subtribe Pterostylidinae (Orchidaceae), reaffirming Pterostylis in the broad senseAustralian Systematic Botany 23: 260–269

Jones, D.L.; Clements, M.A.; Molloy, B.P.J 2002: A Synopsis of the Subtribe Pterostylidinae. Australian Orchid Research 4: 129-146.

Moore, L.B.; Edgar, E. 1970: Flora of New Zealand. Vol. II. Government Printer, Wellington.

Szlachekto, D.L. 2001: Genera et Species Orchidalium 1. Polish Botanical Journal 46: 11-26.

Thorsen, M. J.; Dickinson, K. J. M.; Seddon, P. J. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285-309

This page last updated on 13 Nov 2014