Carex filamentosa
Common names
Stewart Island sedge
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Sedges
Detailed description
Rather densely tufted stoloniferous, pale green to reddish green sedge. Culms 30–120 × 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. Spikes: 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 × 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. edgariae Hamlin, C. libera (Kük.) Hamlin and C. uncifolia Cheeseman. All are small, rhizomatous reddish green sedges with congested, approximate spikes. Of 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. edgariae of inland Otago, C. filamentosa is readily distinguished by its distinctly beaked utricles and much narrower leaves.
Distribution
Endemic. South Island and Stewart Island/Rakiura. In the South Island confined to Southland where scarce. Stewart Island/Rakiura locally common throughout.
Habitat
A species of damp sites in damp ground within montane to subalpine scrub, srhubland and open grassland.
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.
- 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 | At Risk – Naturally Uncommon | Qualifiers: Sp, DPS, DPT, RR
Threats
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.
Detailed taxonomy
Genus
Family
Synonyms
None
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
October–February
Fruiting
October–May
Life cycle and dispersal
Nuts surrounded by inflated utricles are dispersed by granivory and wind (Thorsen et al., 2009).
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.
Other information
Where To Buy
Not commercially available.
Plant of the Month
This plant has been featured as a Plant of the Month – see Trilepidea: NZPCN newsletter for April 2017 for the full story.
Etymology
carex: Latin name for a species of sedge, now applied to the whole group.
filamentosa: Thread-like
Manaaki Whenua Online Interactive Key
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.
CARFIL
Previous conservation statuses
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.
- 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.
2017 | At Risk – Naturally Uncommon | Qualifiers: DP, RR, Sp
2012 | At Risk – Naturally Uncommon | Qualifiers: RR, Sp
2009 | At Risk – Naturally Uncommon
2004 | Range Restricted
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
Description adapted from Moore and 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.