Machaerina tenax
Biostatus
Native
Category
Vascular
Structural class
Sedges
Simplified 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.
Detailed description
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.
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.
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – these interim threat classification statuses has not been assessed by the NZTCS panel.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2023 | Not Threatened
Detailed taxonomy
Family
Cyperaceae
Synonyms
Lampocarya tenax Hook.f.; Cladium tenax (Hook.f.) Druce; Baumea tenax (Hook.f.) Blake
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
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.
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
FACW: Facultative Wetland
Usually is a hydrophyte but occasionally found in uplands (non-wetlands).
Other information
Etymology
tenax: Tough
NVS code
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.
MACTEN
Previous conservation statuses
2017 | Not Threatened
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Referencing and citations
References and further reading
Moore LB, Edgar E. 1970. Flora of New Zealand, Volume II. Indigenous Tracheophyta: Monocotyledones except Gramineae. Government Printer, Wellington, NZ. 354 p.
Thorsen MJ, Dickinson KJM, Seddon PJ. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285–309.
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange (25 March 2012). Description adapted from Moore & Edgar (1970)
Some of this factsheet information is derived from Flora of New Zealand Online and is used under a Creative Commons Attribution 3.0 New Zealand licence.
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)