The New Zealand Plant Conservation Network

Species

Pterostylis agathicola

Etymology

Pterostylis: winged column

Common Name(s)

Kauri 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 agathicola D.L.Jones, Molloy et M.A.Clem.

Family

Orchidaceae

Flora Category

Vascular - Native

NVS Species Code

PTEAGA

Structural Class

Orchids

Synonyms

Pterostylis graminea var. rubricaulis H.B.Matthews ex Cheeseman nom. inval.; Pterostylis montana var. rubricaulis (H.B.Matthews ex Cheeseman) Hatch nom. inval.

Distribution

Endemic. North Island from Te Paki south to Te Kauri Scenic Reserve in the west and the northern Kaimai Range in the east

Habitat

Coastal to montane (up to 720 m a.s.l). Virtually confined to kauri (Agathis australis (D.Don) LIndl.) dominated forest where it usually found growing in leaf litter close to the trunks of large kauri trees.

Features

Terrestrial tuberous herb growing as solitary plants or in diffuse colonies. Plants dimorphic. Sterile plants 60-100 mm tall; 2-3-leaved; leaves narrowly linear-lanceolate, 30-60 x 3-6 mm, dark green, entire, acute to acuminate. Flowering plants 100-350 mm tall, stems green or pale green, rarely reddish. Leaves 3-4, cauline, widely spaced, spreading; lamina narrowly lanceolate, 40-100 x 5-8 mm, dark green or pale green, sessile, sheathing at base; midrib prominent; margins entire; apex acuminate. Pedicels 10 mm long, slender. Ovary 9-12 mm long, ribbed. Flowers 1(-2), 24-28 mm long, erect or slightly leaning forwards, translucent white and dark green with red brown suffusions at the apex of the galea and lateral sepals; galea gibbous at the base then erect before bending forwards, the apex flat, erect or decurved, the dorsal sepal much longer than the petals. Dorsal sepal ovate-lanceolate in outline when flattened, 33-37 x 12-16 mm, prominent expanded near the base then tapered to the long-acuminate apex. Lateral sepals erect, loosely embracing the galea leaving a prominent lateral gap to the petal margins; upper part of sinus flat or shallowly mounded when viewed from the side, with a deep narrow, central notch when viewed from the front; conjoined part 8-11 x 6-9 mm, narrowed to c.2.5 mm wide at the base, tapered into the free points; free points 20-26 mm long, tapered, erect, the tips extending high above the galea. Petals obliquely linear-lanceolate, 17-22 x 3-4 mm, strongly falcate, acuminate, green with white stripes, red-brown towards the apex.. Labellum erect, curved forwards in the distal third, the apex twisted strongly to the right and protruding prominently through the sinus in the set position; labellum hinge ligulate 3 x 2 mm; lamina narrowly ovate-lanceolate to elliptical lanceolate, 9.0-11.0 x 3.0-3.3 mm, dark green to brownish with a darker reddish central callus, apex subobtuse to slightly emarginate; callus 0.6 mm wide near apex, raised; basal appendage 2.5-3.0 mm long, decurved, apex penicillate. Column 12-14 mm long, bent away from the ovary at 45 degrees at the base then erect, green and white; column foot 4 mm long. Column wings 5-6 mm long; basal lobe 3 x 1 mm, at an angle of about 35 degrees. apex obtuse, inner margins incurved, sparsely and shortly ciliate; mid-section 2.5 mm long; green; apical lobe 1 mm long, linear, obtuse. Stigma scutiform 3.0-3.5 x 2.0 mm, medial on the column, raised. Anther 1.8 mm long, very shortly rostrate. Pollinia linear-falcate, 1.3-1.4 mm long, yellow, mealy. Capsules narrowly-ellipsoid, 20-24 x 5-7 mm.

Similar Taxa

Easily recognised by the early flowering habit; mostly reddish stem; 3-4 widely spaced, spreading leaves; large (for size of plant) flowers (24-28 mm long); long and slender, spreading free points on the lateral sepals; and by the labellum apex constricted and twisted to the right. Ecologically it is particularly distinctive through its restriction to kauri forest where it often grows with Diplodium brumalum (L.B.Moore) D.L.Jones, Molloy et M.A.Clem.

Flowering

July - October

Flower Colours

Green,White

Fruiting

August - December

Propagation Technique

Difficult - should not be removed from the wild. Extremely mycorrhizal.

Threats

Not Threatened

Chromosome No.

2n = 44

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 31 Oct 2014