Species

Microtis oligantha

Etymology

Microtis: tiny eared
oligantha: few-flowered

Common Name(s)

Small onion orchid

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 oligantha L.B.Moore

Family

Orchidaceae

Flora Category

Vascular - Native

NVS Species Code

MICOLI

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.

Structural Class

Orchids

Synonyms

None (first described in 1967)

Distribution

Endemic. North, South and Chatham Islands

Habitat

Damp places in tussock grassland, on lake, tarn, river and wetland margins. Coastal to subalpine. Mainly montane to subalpine in the North Island, descending to sea level in the South and Chatham Islands

Features

Terrestrial, glabrous, fleshy, tuberous bright green to dark green perennial herb forming small colonies or occurring as solitary plants. Plants at flowering up to 150 mm tall. Tubers globose to ovoid. Stem erect, terete, fleshy. Leaf solitary, usually overtopping inflorescence (but often damaged and so falling short), bright green to dark green, rarely tinged with red near base, closely sheathing stem for much of length, linear-terete, hollow, up to 200 mm long. Inflorescence a loose raceme up to 30 x 5 mm. Flowers 1-10, up to 2.8 mm diameter, shortly-stalked mostly widely spaced. Perianth green, segments up to 1.8 mm long, widely spreading, thick and fleshy. Dorsal sepal 2.5 mm long, broadly ovate, erect or projecting forwards, cucullate, concave, column-embracing, apex and margins rounded (without recurved apex), smaller than ovary at flowering; lateral sepals much shorter, narrower, mostly acute to subacute, strongly deflexed, apices straight. Petals shorter again, broadly to narrowly obtuse, erect, mostly hidden under dorsal sepal. Labellum sessile, up to 2.0 mm long, green or yellow-green, oblong, slightly narrowed at mid-length; apex bluntly truncate rarely slightly emarginate, not apiculate; margin papillose, shallowly crenate, often thickened, rarely undulate; anterior callus variously developed, verrucose, rather irregular, often raised on a rounded ridge; basal calli conspicuous, dark green, tabular-ovoid to tabular, usually continuous at sides with narrow band of callus behind a transverse, silt-like (not pouched) furrow; labellum sharply deflexed, pendulous aligned more or less parallel to the ovary. Column short, obtuse, base of column mostly broader than 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

Usually smaller than the other species of Microtis and with fewer flowers (up to 10). This species is best recognised by the obtuse rather than acute dorsal sepal whose apex is not upturned, and by the short-oblong to almost quadrate labellum with only shallowly crenate or rarely undulate margins. The labellum calli are indistinct and tabular

Flowering

December - March

Flower Colours

Green

Fruiting

March - May

Propagation Technique

Easily grown in a damp sunny position. Should not be removed from the wild

Threats

Not Threatened

Chromosome No.

2n = 44

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

Where To Buy

Not commercially available

TAXONOMIC NOTES

Chatham Island plants tend to be much larger than those seen on the other New Zealand islands.

Attribution

Fact Sheet prepared for NZPCN by P.J. de Lange 14 April 2007. Description adapted from Moore and Edgar (1970).

References and further reading

Moore, L.B.; Edgar, E. 1970: Flora of New Zealand. Vol. II. Government Printer, Wellington.

This page last updated on 9 Dec 2014