Carex geminata
Common names
cutty grass, rautahi
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Sedges
Detailed description
Rhizomatous, robust bright-green to yellow-green sedge, 0.5–1.2 m tall. Culms 1.5–3.5–(5) mm diam., triangular in cross-section, very sharply scabrid. Basal sheaths dull grey-brown or purple-brown. Leaves numerous, > culms (2)–5–9–(11), wide, double-folded, margins very scabrid. Spikes (10)–15–24, yellow-green, grass-green, or dark-green mottled red or purple, all pedunculate, pendulous, rather narrow, often twisted and “worm-like”. Glumes dark red-purple, (excluding awns) more less same length as utricles, narrow-oblong, truncate or emarginate with a hispid awn of variable length. Utricles (2)–2.3–2.9–(3.5) × 1.2–1.7–(2) mm, biconvex, compressed at base, tapering evenly above, green-, red- or yellow-brown, 3–5-nerved, margins glabrous, beak minute or 0.2 mm long.
Similar taxa
Carex geminata has frequently been confused with C. lessoniana Steud. This species often grows in similar habitats, but can be distinguished by the compact inflorescences, with wider, though smaller, usually erect spikelets, and by distinctly beaked utricles. A similar species C. ternaria Boott is occasionally cultivated on the New Zealand mainland, this species is very much larger (up to 3 m tall), dark green sedge with much larger spikes and glumes which are conspicuously awned. Can also be confused with C. coriacea Hamlin, but the glumes of C. coriacea do not have awns.
Distribution
Endemic. Found throughout the North, South and Stewart Islands.
Habitat
Coastal to lower montane in freshwater wetlands, along river and stream banks, lake margins, and in damp seepages, pond margins and clearings within forest. Preferring fertile to mid-fertile wetlands.
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 | Not Threatened
Detailed taxonomy
Genus
Family
Synonyms
Carex ternaria var. gracilis Cheeseman, C. confusa Hamlin.
Taxonomic notes
This taxon includes two entities, one probably better regarded as an allied but distinct, possibly unnamed species which differs from true C. geminata by its much broader, often yellow-green leaves, longer narrower spikelets, preference for open sunny sites within coastal and lowland wetlands, and also by distinct differences within the nrDNA ITS sequence region.
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
(September)–October–November–(December)
Fruiting
October–March
Life cycle and dispersal
Nuts surrounded by inflated utricles are dispersed by granivory and wind (Thorsen et al., 2009).
Propagation technique
Easily grown from fresh seed and by the division of established plants. Although a wetland species, C. geminata will grow well in most soils and moisture regimes. Does best in full sun.
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
Cultivation
Not commonly cultivated, and plants offered by this name by many nurseries are usually other quite unrelated species, including the Northern Hemisphere C. pendula and the New Zealand subantarctic endemic C. ternaria.
Etymology
carex: Latin name for a species of sedge, now applied to the whole group.
geminata: Twinned
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.
CARGEM
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 | Not Threatened
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Regional conservation statuses
Otago: 2024 | Regionally Not Threatened
The regional threat classification system leverages off the national assessments in the NZTCS, providing information relevant for the regional context. Otago conservation status information is sourced from the “Regional conservation status of indigenous vascular plants in Otago” Jarvie S et al. (2024) report.
Auckland: 2025 | Regionally Not Threatened | Qualifiers: DPS, DPT
The regional threat classification system leverages off the national assessments in the NZTCS, providing information relevant for the regional context. Auckland conservation status information is sourced from the “Conservation status of vascular plant species in Tāmaki Makaurau / Auckland” Simpkins E et al. (2025) report.
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 (10 August 2006). 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.