Pterostylis tristis
Synonyms
Hymenochilus tristis (Colenso) D.L.Jones, M.A.Clem. et Molloy
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.
HYMTRI
Chromosome number
2n = 52
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 | At Risk – Declining | Qualifiers: DP, EF, Sp
Previous conservation statuses
2009 | At Risk – Naturally Uncommon | Qualifiers: DP, EF
2004 | Sparse
Distribution
Endemic. North, South and Stewart Islands. In the North Island scarce being known from a few old gatherings made between the Rangipo Desert and Hawkes Bay. South Island east of the main ranges from North Canterbury south. Stewart Island, known from one old record.
Habitat
Lowland to subalpine (confined to upper montane to subalpine in the North Island). A species of open ground, usually in short tussock grassland within intermontane basins, along river flats and terraces, and also in open ground within grey scrub. It may also grow within mainly exotic pastures and along roadside verges, in loose gravel or shingle, or within sparsely vegetated gaps amongst boulders.
Features
Diminutive orchid mainly of short tussock grassland. Plants rather stout, 20-100 mm tall when flowering. Stem more or less hidden by conspicuous leafy bracts. Rosette leaves fleshy to fleshy-coriaceous, numerous, these 5-15 x 3-10 mm; brown-green, dark to yellow-green, somewhat glaucous, rhombic, more or less alveolate, lamina tapering into a broadly winged petiole; cauline leaves similar but smaller and sheathing. Inflorescence a raceme of 1-6(-8) flowers, each partially enclosed within a sheathing floral bract; perianth green, greenish to brownish-green with pale stripes. Dorsal sepal 5-10 mm, broad, apiculate; lateral sepals slightly shorter, almost completely fused into a flat, apically bidentate lamina, this strongly deflexed in fully opened flowers. Petals shorter than dorsal sepal, the anterior minutely (but distinctly) denticulate. Labellum, short and squat, broadly obtuse, extended backwards into a smoothly rounded appendage with a low, somewhat thickened median ridge. Column short and broad; wings broader than long, ciliate over most of the free margins; stigma broadly ovate.
Similar taxa
Could only be confused with the South Island endemic Pterostylis tanypoda from which it differs in its darker often brownish-green rather than glaucous foliage and usually brownish-green rather than uniformly green flowers whose labellum base possesses a backward (reflexed) or decurved appendage, rather than a prominent forward-pointing knob.
Flowering
September - January
Flower colours
Brown, Green
Fruiting
October - April
Life cycle
Minute seeds are wind dispersed (Thorsen et al., 2009).
Propagation technique
Difficult - should not be removed from the wild
Threats
An easily overlooked orchid of mainly short tussock grasslands. Herbarium data suggests that it is naturally uncommon and biologically sparse. However, it is very easily overlooked. Plants have been found growing in pastures dominated by exotic grasses and also along roadside verges. In the North Island it needs to be surveyed for, as it the areas in which it was recorded retain plenty of suitable habitat and the species is probably still there. Over all the exact conservation status of this species requires a more critical field survey.
Etymology
pterostylis: Winged column
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 Sheet prepared for NZPCN by P.J. de Lange (14 April 2007). Description based on Moore & Edgar (1970) (as Pterostylis mutica) and Colenso (1886) (as P. tristis).
References and further reading
Colenso, W. 1886: A Description of some newly-discovered and rare Indigenous Plants: being a further Contribution towards the making known the Botany of New Zealand. Transactions and Proceedings of the New Zealand Institute 18: 256-287.
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.; Molloy, B. P. J.; Clements, M. A. 1997: Six new species of Pterostylis R.Br. (Orchidaceae) from New Zealand. The Orchadian 12(6): 266-281.
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. I. Government Printer, Wellington.
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
Szlachekto, D.L. 2001: Genera et Species Orchidalium 1. Polish Botanical Journal 46: 11-26.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Pterostylis tristis Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/pterostylis-tristis/ (Date website was queried)