The New Zealand Plant Conservation Network

Species

Pterostylis porrecta

Etymology

Pterostylis: winged column

Common Name(s)

Shrimp-flowered Greenhood

Current Conservation Status

2012 - At Risk - Naturally Uncommon

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 - Naturally Uncommon
2004 - Sparse

Qualifiers

2012 - Sp

Authority

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

Family

Orchidaceae

Flora Category

Vascular - Native

NVS Species Code

PTEPOR

Structural Class

Orchids

Synonyms

None (first described in 1997)

Distribution

Endemic. North and South Islands.

Habitat

Lowland to montane. Usually in deeply shaded, damp scrub and light forest. Also on ultramafic rock.

Features

Terrestrial tuberous herb growing in diffuse colonies. Sterile plants 20-50 mm tall, 3-4-leaved; leaves linear to linear-lanceolate, 40-70 x 4-6 mm, dark green, margins entire, apex acute to acuminate. Flowering plants 60-200 mm tall. Leaves 4-5, cauline, obliquely erect to spreading, sometimes arcuate; lamina linear-lanceolate, 45-120 x 4-6 mm, sessile, sheathing at the base; margins entire; apex acute to acuminate. Pedicel 10 mm long, slender. Ovary narrowly ellipsoid, 7-10 mm long, yellow-green, ribbed. Flower solitary, 18-22 mm long, semi-nodding, translucent white and pale green, darker towards the tip of the galea, the points of the sepals pale pink; galea shallowly gibbous at the base then leaning forwards before decurving in a shallow curve to the apex, the dorsal sepal much longer than the petals. Dorsal sepal ovate-lanceolate in outline when flattened, 19-22 x 9-11 mm, prominently expanded in the proximal third then gradually tapered to the acuminate apex. Lateral sepals obliquely erect top nearly horizontal, held well away from the galea, leaving a very wide lateral gap to the marginal petals; most of the labellum visible from the side through this gap; upper part of sinus flat when viewed from the side, sloping to a broad v when viewed from the front; internally the sinus projecting inwards as a small platform-like structure; conjoined part 7-9 x 5-6 mm wide at the top, narrowed t0 1.6 mm wide at the base, the margins inrolled towards the apex and tapered into the free points, the free points 13-15 mm long, narrowly tapered to an attenuate apex, curved forwards, the tips often shallowly curved. Petals oblong-lanceolate, 16-19 x 3.0-3.5 mm, nearly straight, acute to acuminate, green with a white central area and two or three green stripes; flange vestigial. Labellum obliquely erect, shallowly curved forwards distally, the apex not protruding through the sinus in the set position; labellum hinge ligulate, 3 x 1 mm; lamina oblong, 8.0-9.0 x 2.3-2.5 mm, green to brownish green with a darker green central callus, apex obtuse, pinkish; callus 0.5 mm wide near the apex, raised; basal appendage 2.6-3.0 mm long, decurved. apex penicillate. Column 10-12 mm long, bent away from the ovary at about 50 degrees at the base then obliquely erect, green and white;column foot 3 mm long. Column-wings 4.5-5.0 mm long; basal lobe 2.0 x 0.7 mm, at an angle of 40 degrees. apex broadly obtuse, inner margins incurved. sparsely ciliate; mid-section 1.5 mm long, green; apical lobe 0.8 mm long, obtuse. Anther 1 mm long, shortly rostrate. Pollinia linear-clavate, 1.0-1.2 mm long, yellow, mealy. Stigma narrowly scutiform, 5.0-5.5 x 1.0-1.4 mm, situated just below column-wings raised. Capsule subcylindrical to broadly ellipsoid, 8-14 x 4-6 mm, initially yellow-green maturing grey.

Similar Taxa

Recognised by the small, semi-nodding, pale green and white flowers; by the lateral sepals being obliquely erect to nearly horizontal and held well away from the galea leaving a wide lateral gap exposing most of the labellum in the set position; by the pale pink narrowly tapered free points of the lateral sepals with the tips curled forwards; and by the straight petal; and oblong labellum.

Flowering

November - January

Flower Colours

Green,White

Fruiting

January - March

Propagation Technique

Difficult - should not be removed from the wild.

Threats

A biologically sparse species, known from widely scattered sites. It is possibly threatened by plant collectors.

Chromosome No.

2n = 44

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 31 Oct 2014