Pterostylis agathicola
Common name
kauri greenhood
Synonyms
Pterostylis graminea var. rubricaulis H.B.Matthews ex Cheeseman nom. inval.; Pterostylis montana var. rubricaulis (H.B.Matthews ex Cheeseman) Hatch nom. inval.
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.
PTEAGA
Chromosome number
2n = 44
Current conservation status
The threat classification 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) – more information about this can be found on the NZTCS website 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. Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – a suggested threat classification status has not been assessed by the NZTCS panel.
Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | Not Threatened
Previous conservation statuses
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
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.
Manaaki Whenua Online Interactive Key
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.
Etymology
pterostylis: Winged column
Where To Buy
Not commercially available
Attribution
Fact Sheet prepared for NZPCN by P.J. de Lange 14 April 2007: Description based on Jones et al. (1997).
References and further reading
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: 266-281
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Pterostylis agathicola Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/pterostylis-agathicola/ (Date website was queried)