Lampocarya tenax Hook.f.; Cladium tenax (Hook.f.) Druce; Baumea tenax (Hook.f.) Blake
Vascular – Native
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.
Current conservation status
The conservation 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). 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.
2012 | Not Threatened
Previous conservation statuses
2009 | Not Threatened
2004 | Not Threatened
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.
Endemic. New Zealand: North, South, Stewart and Chatham Islands (but scarce in Northland and much of the eastern South Island).
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.
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.
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.
December - February
Fruits present throughout the year
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.
Fact sheet prepared for NZPCN by P.J. de Lange (25 March 2012). Description adapted from Moore & Edgar (1970)
References and further reading
Moore, L.B.; Edgar, E. 1970: Flora of New Zealand. Vol. II. Government Printer, Wellington.
Thorsen, M. J.; Dickinson, K. J. M.; Seddon, P. J. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 2009 Vol. 11 No. 4 pp. 285-309
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Machaerina tenax Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/machaerina-tenax/ (Date website was queried)