The New Zealand Plant Conservation Network

Species

Pterostylis banksii

Etymology

Pterostylis: winged column
banksii: Named after Sir Joseph Banks, 1st Baronet, GCB, PRS (24 February 1743 - 19 June 1820) was an English naturalist, botanist and patron of the natural sciences.

Common Name(s)

Tutukiwi, Greenhood

Current Conservation Status

2012 - Not Threatened

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 - Not Threatened
2004 - Not Threatened

Authority

Pterostylis banksii A.Cunn.

Family

Orchidaceae

Flora Category

Vascular - Native

NVS Species Code

PTEBAN

Structural Class

Orchids

Synonyms

Pterostylis emarginata Colenso, Pterostylis macrophylla A.Cunn. ex Hook.f. nom. illegit.

Distribution

Endemic. North, South, Stewart and Chatham Islands

Habitat

Coastal to montane (up to 800 m a.s.l.). In indigenous or exotic forests and shrubland.

Features

Terrestrial, tuberous, glabrous, spring to summer-green perennial herb, forming dense colonies of numerous plants through vegetative extension. Plant at flowering 100-680 mm tall. Stem stiffly erect, smooth, dark green to reddish green, internodes shorter than leaves throughout. Leaves 4-6, sessile, stiffly erect to curved and more or less drooping, dark green to yellow green with entire margins; in sterile plants lamina of similar size, oblong-elliptic to broadly lanceolate; in flowering plants lamina changing in size from base to top of stem; lamina of largest leaves 50-250 x 10-20 mm, lanceolate to linear-lanceolate, keeled, often with 2 laterals on either side of midrib, apex acuminate to long acuminate, base wider than rest of lamina broadening into a long sheathing base; mostly overtopping flower. Flower 1(-2), erect, front mostly green finely striped with white, stripes of white widening toward back of galea with green narrowing, back of galea sometimes completely white. Ovary erect. Dorsal sepal distinctly broadly ovoid to subglobose, 25-50 mm tall, erect, distal portion usually more or less horizontal in fully open flowers, apex tapering to a long caudate, upturned tip up to 25 mm long and usually exceeding the lateral sepals; lateral sepals diverging at a narrow angle, caudae of lobes up to 20 mm long, tapered, erect or strongly deflexed backwards, not or scarcely decurved. Petals much shorter than dorsal sepal with acuminate apices. Labellum elliptic-oblong, scarcely arched, flat in cross-section, narrowing slightly towards tip, bending forwarding smoothly and symmetrical, protruding from lateral sepals sinus, midrib initially prominent soon evanescent toward the obtuse, often cucullate apex. Column as tall as or slightly taller than labellum; stigma ellipsoid, scarcely distinguished from column and rather flat.

Similar Taxa

Most likely to be confused with to P. patens Colenso, from which it differs by the spreading rather than stiffly erect, lanceolate to linear-lanceolate rather than broadly lanceolate to linear-lanceolate (grassy) leaves which usually overtop the flower; by the dorsal sepal which projects forwards and upwards in a long (up to 23 mm ) tapered caudae, rather than being strongly deflexed downwards; and by lateral sepals whose caudae are erect or deflexed backwards but never strongly deflexed back and down, sometimes meeting at the back of the ovary. Both species are frequently sympatric in the central North Island. The distinction between P. banksii and P. australis Hook.f. can at times be difficult. Pterostylis australis differs from P. banksii by the shorter, broader leaves which mostly just reach rather than overtop the flower, by its much shorter dorsal sepal and consistently arched labellum. Pterostylis banksii has a superficial similarity to Pterostylis irwinii D.L.Jones, Molloy et M.A.Clem., which differs by its very slender, erect, dark green to reddish green leaves, incurved lateral sepals which cause the sepals to prominently lean forward of the rest of the flower thereby forming an inward turning jug spout at the sinus, and by the green, broadly lanceolate to oblong-lanceolate labellum, which has a distinct black central ridge terminating in a reddish cupular apex.

Flowering

September - November

Flower Colours

Green,White

Fruiting

November - February

Propagation Technique

Difficul. For cultivation requirements see other Pterostylis.

Threats

Not Threatened

Chromosome No.

2n = 44

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 31 Oct 2014