The New Zealand Plant Conservation Network

Species

Pterostylis paludosa

Etymology

Pterostylis: winged column
paludosa: Of the swamps

Common Name(s)

Swamp Greenhood

Current Conservation Status

2012 - At Risk - Declining

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 - At Risk - Declining
2004 - Serious Decline

Qualifiers

2012 - RR

Authority

Pterostylis paludosa D.L.Jones, Molloy et M.A.Clem

Family

Orchidaceae

Flora Category

Vascular - Native

Structural Class

Orchids

Synonyms

Pterostylis furcata var. linearis Hatch

Distribution

Endemic: North, South and Stewart Islands. In the North Island present from Great Barrier Island to Waiouru. In the South Island confined to the west from north-west Nelson to about Westport.

Habitat

Peat bogs and heathlands, usually in well-lit sites amongst mosses and sedges.

Features

Terrestrial tuberous herb growing in dense colonies. Sterile plants 40-80 mm tall, 2-4-leaved; leaves linear-lanceolate, 25-60 x 7-11 mm, pale green to yellow-green (rarely dark green), margins entire or finely denticulate, apex subacute. Flowering plants 80-900 mm tall.Leaves 3-4, cauline, obliquely erect, pale green to yellowish green; lamina linear-lanceolate, 50-80 x 7-11 mm wide, sessile, sheathing at the base; margins entire or rarely finely denticulate; apex subacute. Pedicel 20-30 mm long, slender. Ovary 9-17 mm long, asymmetric, ribbed. Flower solitary, 18-20 x 5-6 mm, erect, translucent white and pale green to yellow green; galea gibbous at the base then erect before curving forwards in a shallow curve to the apex, the dorsal sepal slightly longer than the petals. Dorsal sepal ovate-lanceolate in outline when flattened, 24-26 x 13-16 mm, prominently expanded in the proximal third then suddenly narrowed and gradually tapered to the acute apex. Lateral sepals erect, tightly embracing the galea, with no lateral gap; upper part of the sinus very shallowly curved when viewed from the side, sloping to a narrow v when viewed from the front, scabrous; conjoined part 9-11 x 6-9 mm wide at the top, narrowed to 4 mm wide at the base, tapered into the free points; free points 9-11 mm long, tapered, erect, the tips extending just above galea. Petals obliquely oblong-lanceolate, 14-20 x 305 mm, falcate, acute, green with a white central area; flange vestigial. Labellum erect, curved suddenly forwards near the apex, raised; basal appendage 2.5-3.0 mm long, decurved, apex penicillate. Column 11.0-13.5 mm long, erect, green and white; column foot 1.5 mm long. Column wings 5.5-7.0 mm long; basal lobe 3.0 x 0.8 mm, at an angle of about 40 degrees, apex obtuse, inner margins incurved, sparsely ciliate; mid-section 2.5 mm long; green; apical lobe linear 1.2 mm long, obtuse. Stigma cordate, 3.0-3.3 x 2.0-2.2 mm, situated just below the column wings, raised. Anther 1.4 mm long, obtuse. Pollinia linear, 2 mm long, yellow, mealy. Capsules narrowly ellipsoid 15-17 x 3.0-3.5 mm, initially yellow green, maturing grey.

Similar Taxa

Pterostylis micromega Hook.f. and an unnamed swamp dwelling orchid allied to P. graminea Hook.f., grow with and may be confused with P. paludosa. When flowering P. paludosa and P. micromega are clearly different, but sterile specimens are harder to separate. Basal leaves of P. micromega are distinctly broader, spreading and have undulating margins. The basal leaves of the unnamed orchid allied to P. graminea are much smaller, finer, and grass-like. Flowering specimens are distinctive because the flowers are much smaller, and very conspicuously striped white and dark green.

Flowering

September to January

Flower Colours

Green,White

Fruiting

November to March

Propagation Technique

Easily grown in a pot partially submerged in water. However, as with all indigenous orchids, this species should not be removed from the wild.

Threats

Habitat loss through wetland drainage, and natural succession to taller vegetation. This species requires frequent disturbance to maintain itself. It is especially abundant following peat fires. The species is also at risk from plant collectors.

Chromosome No.

2n = 44

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 31 Oct 2014