The New Zealand Plant Conservation Network

Species

Microtis unifolia

Etymology

Microtis: tiny eared
unifolia: single leaved

Common Name(s)

Onion-leaved orchid, microtis

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

Microtis unifolia (G.Forst.) Rchb.f.

Family

Orchidaceae

Flora Category

Vascular - Native

NVS Species Code

MICUNI

Structural Class

Orchids

Synonyms

Ophrys unifolia Forst.f.; Epipactis porrifolia Schwartz; Microtis banksii Hook; Microtis longifolia Col.; Microtis papillosa Col.

Distribution

Indigenous. In New Zealand present on the Kermadec, Three Kings, North, South, Stewart and Chatham Islands. Exact New Zealand distribution unclear due to confusion with an allied, later flowering entity. Present also in Australia, Norfolk Island, New Caledonia, Indonesia, the Philippines, Japan and China.

Habitat

Coastal to montane. Widespread in mainly disturbed or successional habitats. Common in urban areas in lawns, verges, roadside banks and cuttings and even amongst moss filled crevices on old buildings.

Features

Terrestrial, glabrous, colony forming, fleshy, tuberous bright green to dark green perennial herb. Plants at flowering up to 1 m tall. Tubers globose to ovoid. Stem erect, terete, often striated. Leaf solitary, usually overtopping inflorescence, bright green to dark green, rarely tinged with red near base, closely sheathing stem for much of length, linear-terete, hollow, up to 800 mm long. Inflorescence a raceme up to 300 x 10 mm. Flowers 6-100, up to 4 mm diameter, shortly-stalked and closely spaced, more or less overlapping. Perianth green, segments up to 2.5 mm long, widely spreading, thick and fleshy. Dorsal sepal 3 mm long, broadly ovate, erect or projecting forwards, cucullate, concave, column-embracing, acute with apex usually slightly turned upwards, smaller than ovary at flowering; lateral sepals much shorter and narrower, acute, strongly deflexed, apices tending to coil under. Petals shorter still, obtuse, erect, usually partially hidden under dorsal sepal. Labellum sessile, up to 2.5 mm long, green or yellow-green, oblong, sharply deflexed or decurved, pinched in at about mid-length to form a slight to obvious waste; apex truncate or slightly emarginate, not apiculate though often folded to appear so; margin papillose and usually also crenate and undulate; anterior callus variously developed, verrucose, rather irregular, often raised on a rounded ridge; basal calli dark green, oval, prominent, and usually continuous at sides with narrow band of callus behind transverse, silt-like (not pouched) furrow; labellum standing away from ovary at a very narrow angle. Column short, obtuse, base of column about as broad as stigma, wings mostly membranous throughout. Anther terminal, erect, situated above stigma, hemispherical, pollinia spheroidal, pollen granular. Stigma broadly ovate; rostellum ovate Capsules broadly ovoid, ovoid-ellipsoid, brown when ripe.

Similar Taxa

Distinguished from M. parviflora by the more or less oblong rather than triangular labellum. Microtis oligantha is similar but has fewer flowers (up to 10 cf. up to 100); the dorsal sepal of M. unifolia is acute and the apex usually sharply uptilted rather than obtuse with the apex not tilted upwards; M. oligantha has a short-oblong to almost quadrate labellum with shallowly crenate or undulate margins, M. unifolia has a long-oblong labellum usually narrowed at mid-length, and with deeply crenate and unudulose margins. The basal calli of M. oligantha are indistinct and tabular, while those of M. unifolia are oval and prominent.

Flowering

August - November

Flower Colours

Green

Fruiting

October - March

Propagation Technique

Easily grown and inclined to become invasive. Often present as a pot contaminant in nurseries.

Threats

Not Threatened

Chromosome No.

2n = 88

Endemic Taxon

No

Endemic Genus

No

Endemic Family

No

This page last updated on 21 Jan 2015