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
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 sense. Australian 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