Carex filamentosa


Carex: Latin name for a species of sedge, now applied to the whole group.
filamentosa: thread-like

Common Name(s)

Stewart Island Sedge

Current Conservation Status

2012 - At Risk - Naturally Uncommon

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 - At Risk - Naturally Uncommon
2004 - Range Restricted


2012 - RR, Sp


Carex filamentosa Petrie



Flora Category

Vascular - Native

NVS Species 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.

Structural Class





Endemic. South and Stewart Islands. In the South Island confined to Southland where scarce. Stewart Island locally common throughout.


A species of damp sites in damp ground within montane to subalpine scrub, srhubland and open grassland.


Rather densely tufted stoloniferous, pale green to reddish green sedge. Culms 30-120 x 0.5 mm, terete, faintly striated. Leaves up to twice the length of the culms, 0.5 – 1 mm wide, plano-convex, nerved on the under surface, smooth on the upper, rather finely scabrid toward the apex. Inflorescence of 2-4 spikes; these crowded toward the top of the culm, usually with at least some of the lowermost distant. Uppermost spike rather slender, male; remaining spikes mainly female, shortly pedunculate, rarely with some male flowers toward the top. Bracts subtending spikes, long, filiform and leaf-like. Glumes < or sometimes = to utricles, ovate, chartaceous to membranous, pale cream, brown- or red-flecked, midrib distinct extended as a smooth finely scabrid awn. Utricles 2.5-3 x 1.5 mm, plano-convex or subtrigonous, elliptic-lanceolate, light brown with reddish brown markings towards the beak, distinctly nerved; beak slightly narrowed, 0.5 mm long, margins smooth, crura finely bifid; stipe minute. Stigmas 3. Nut 1.5 mm long, red-brown, trigonous, obovoid

Similar Taxa

Carex filamentosa is closely allied to C. edgarae Hamlin, C. libera (Kük.) Hamlin and C. uncifolia Cheeseman, all are small, rhizomatous reddish green sedges with congested, approximate spikes. From these species C. filamentosa is most similar to C. uncifolia from which it differs by its distinctly wide spreading stoloniferous rather than shortly rhizomatous habit and by the shortly pedunculate rather than sessile female spikes. From the North West Nelson endemic C. libera, C. filamentosa is distinguished by its southern South Island and Stewart Island distribution, plano-convex leaves and distinctly beaked utricles. From C. edgarae of inland Otago, C. filamentosa is readily distinguished by its distinctly beaked utricles and much narrower leaves.


October - February


October - May

Propagation Technique

Easily grown from division of whole plants and fresh seed. Does well in a pot or in a damp sunny site. Tolerant of most garden soils and situations. Does not like drought or excessive humidity.


A naturally uncommon sedge which is by and large confined to Stewart Island. It may be threatened in some parts of its Southland coastal range.

Endemic Taxon


Endemic Genus


Endemic Family


Life Cycle and Dispersal

Nuts surrounded by inflated utricles are dispersed by granivory and wind (Thorsen et al., 2009).

Where To Buy

Not commercially available.


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.

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

This page last updated on 29 May 2014