The New Zealand Plant Conservation Network

Species

Thelymitra colensoi

Etymology

Thelymitra: woman's hat
colensoi: Named after William Colenso (7 November 1811 - 10 February 1899) who was a Cornish Christian missionary to New Zealand, and also a printer, botanist, explorer and politician.

Common Name(s)

Colenso's sun orchid

Current Conservation Status

2012 - Data Deficient

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

Thelymitra colensoi Hook.f.

Family

Orchidaceae

Flora Category

Vascular - Native

NVS Species Code

THECOL

Structural Class

Orchids

Synonyms

Thelymitra intermedia Berggr.

Distribution

Endemic. Three Kings, North, South and Stewart Islands. Rather widespread and very common in northern New Zealand. Often on offshore islands.

Habitat

Coastal to montane (up to 700 m a.s.l.). Usually in open ground, or on clay pans. Frequent in successional shrublands and open forest. Common in pine plantations. Together with members of the T. longifolia J.R.Forst. et G.Forst. agg, this is the most commonly encountered sun orchid on northern offshore islands. Frequently found growing with T. pauciflora R.Br.

Features

Terrestrial, tuberous, glabrous late winter to summer-green perennial herb. Leaf solitary, erect, to suberect, or trailing ground, fleshy, deeply channelled and keeled, prominently v-shaped in cross section, 80-300 x 3-6(-8) mm, dark or light green base, linear-lanceolate to lanceolate, apex acute, margins and upper and lower surfaces often spotted with rust, closely sheathing at base. Inflorescence racemose, 80-300 x 1-1.5(-2.5) mm, slender, straight, wiry, dark green, reddish green or yellow-green. Bracts 1-2(-3), 10-30 x 3-4 mm, linear to linear-lanceolate, closely sheathing, acute to acuminate, dark green or reddish green. Flowers 1-7, 10-15 mm diameter, pale blue, mauve to pink; only opening on very hot, still, sunny days, autogamous. Perianth segments 6-8 x 3-5 mm, concave, shortly apiculate; dorsal sepal lanceolate to ovate, obtuse to subacute; lateral sepals lanceolate to ovate, acute; petals broadly lanceolate to ovate, subacute; labellum elliptic to lanceolate, acute, slightly smaller than other segments. Column 3.5-4.2 x 2.0-2.5 mm, erect, pale blue to mauve; post anther lobe slightly cucullate and curved, usually dark brown to reddish-brown or red, apex bluntly entire, bright yellow; post anther lobe extension minute; auxillary lobes absent; column arms converging, 0.5-0.8 mm long, bent sharply upwards near the middle at 90 degrees, each furnished with a subterminal tuft of sparse white cilia. Anther inserted above central column. Stigma situated at base of column.

Similar Taxa

Thelymitra colensoi Hook.f. is rather similar and often confused with T. pauciflora R.Br.. However, T. colensoi, is an endemic species which is much smaller and more slender, with fewer flowers (up to 5) which almost never open, and then only one at a time. The flowers are certainly autogamous and probably also cleistogamous. The petals are pale blue to pale pink. The post-anther lobe is not as thin or as deeply inturned as T. pauciflora, pale blue to pink, grading through brown to reddish-brown with a pale yellow to yellow margin. The post anther lobe is rather similar to T. longifolia G.Forst though much more deeply cleft. Thelymitra colensoi is often known in New Zealand by its later synonym T. intermedia Berggren

Flowering

July - December

Flower Colours

Red / Pink,Violet / Purple

Fruiting

September - March

Propagation Technique

Very easily grown in a sunny, well drained site. Often naturalises in gardens within urban areas abutting indigenous vegetation in northern New Zealand. This species is a common contaminant of pine bark and is often found growing within inner city traffic islands and planter boxes in which pine bark mulch has been strewn. Although easily cultivated, like all orchids it should not be removed from the wild.

Threats

Not Threatened

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 20 Oct 2014