The New Zealand Plant Conservation Network

Species

Machaerina tenax

Etymology

tenax: tough

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

Machaerina tenax (Hook.f.) Koyama

Family

Cyperaceae

Brief Description

Grass-green, reed-like tufted sedge. Culms narrow, terete, internally septate culms. Inflorescences dark brown to black-brown,spike-like with narrow and pointed apices; inflorescence branches tapered, more or less widely spaced, spikelets clustered. Nut smooth, yellow when mature.

Flora Category

Vascular - Native

NVS Species Code

MACTEN

Structural Class

Sedges

Synonyms

Lampocarya tenax Hook.f.; Cladium tenax (Hook.f.) Druce; Baumea tenax (Hook.f.) Blake

Distribution

Endemic. New Zealand: North, South, Stewart and Chatham Islands (but scarce in Northland and much of the eastern South Island).

Habitat

Coastal to subalpine. Usually on peat in bogs, around tarns and slow flowing peaty streams. However, Machaerina tenax has also been found growing in poorly draining pasture and in rough pasture land in hill country, at the back of estuarine swamps (where it may grow with M. juncea and M. complanata) and under willow in willow car.

Features

Stout, densely tufted, light-green (grass-green) perennial. Rhizome 2–3 mm diameter, with culms closely and evenly spaced along it. Culms, 0.15–1.65 m tall, 0.5–1.5 mm wide, slender, terete, rigidly pliant and wiry. Leaves reduced to basal, reddish pink, sheathing bracts; the uppermost often furnished with a terete lamina like the culm. Inflorescence 50–250 mm long, very narrow, spike-like; branchlets remote, slender, erect from sheathing mucronate bracts. Spikelets 6–8 mm long, ± distant, not fascicled, light grey-brown or reddish, distinct at the tips of the branchlets, 1-flowered. Glumes usually 3, 2 lower glumes ± membranous, lanceolate, shortly acuminate, the uppermost glume longer, spreading with maturation of the fruit. Nut, including beak, c.2.5 × 1.5 mm, yellow, ovoid (trigonous when immature), narrowed below to a short, dark brown stalk, narrowed above to a dark brown, pyramidal beak, c.1 mm long, rounded at the tip.

Similar Taxa

Machaerina tenax is recognised by the grass-green, narrow, terete, internally septate culms; dark brown to black-brown, spike-like inflorescences which narrow toward and are at pointed at the apex; by the more or less approximate spikelet branchlets; and by the yellow, smooth-surfaced nut.

Flowering

December - February

Fruiting

Fruits present throughout the year

Propagation Technique

Difficult. Can be grown from fresh seed but slow to establish. Resents root disturbance. Plants seem to flourish best if established first in untreated pine saw dust. Machaerina tenax is an attractive species that does well when planted in seepages in full sun or around ponds. It prefers a moderately acidic substrate.

Threats

Not Threatened

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

This page last updated on 16 Jan 2017