Carex diandra
Common names
sedge
Biostatus
Native
Category
Vascular
Structural class
Sedges
Detailed description
Rhizomatous; loosely tufted, non tussock-forming, pale or bright green (rarely glaucous green), sedge. Shoots arising singly from the rhizome. Rhizome c. 2 mm diameter, loosely covered by dark brown sheaths, roots, fibrous, chestnut-brown; shoots approximate, 2–3 mm diameter at base including basal sheaths. Culms 150–550 × c. 1 mm, wiry, trigonous, smooth below, angles scabrid above; basal sheaths dark grey-brown. Leaves < culms, 1.5–3.0 mm wide, channelled, scabrid on the edges, becoming triquetrous towards the tip. Inflorescence 15–50 mm long, a compound spike, with a few spikes distant below and ± spikes clustered above, greenish brown, rarely subtended by a leaf-like bract ± = inflorescence. Spikes c. 5 mm long, androgynous, male flowers terminal. Glumes = or slightly < utricles, ovate, brown with wide membranous margins, midrib excurrent, finely scabrid in lower glumes. Utricles 3.0–3.5 × 1.5–2.0 mm, plano-convex, occasionally unequally biconvex, broadly ovoid, with short distinct nerves radiating from the base on the convex face, but smooth on the flat face, shining, dark brown; beak c. 1 mm long, sub-pyramidal, light brown, margins scabrid, orifice bifid; stipe minute, c. 0.2 mm long, very narrow. Stigmas 2. Nut 1.5 mm long, biconvex or subtrigonous, obovoid, very much narrowed towards the base, dull brown.
Similar taxa
Somewhat similar to Carex secta Boott, C. appressa R.Br. and C virgata Sol. ex Boott but easily distinguished by the slender, wiry, loosely tufted growth habit, usually much denser spicate panicles with the males at the top, and by the ovoid, swollen long-beaked utricles that are smooth on one side but ribbed on the other.
Distribution
Indigenous. New Zealand: North and South Islands. Uncommon in the North Island and mainly found south of the Central Volcanic Plateau. More widespread in the South Island. Also present throughout the North Hemisphere and most of the Southern Hemisphere.
Habitat
Coastal to subalpine in open, moderately fertile to mid oligotrophic wetlands developed on river flats, within forest or in short or tall-tussock grasslands.
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 | Qualifiers: SO
Detailed taxonomy
Family
Cyperaceae
Synonyms
None
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Flowering
October–December
Fruiting
December–May
Life cycle
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. diandra will grow well in most soils and moisture regimes. Does best in full sun. This species could benefit from some selection, for example, some wild forms have rather attractive glaucous foliage.
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]
OBL: Obligate Wetland
Almost always is a hydrophyte, rarely in uplands (non-wetlands).
Other information
Where To Buy
Not Commercially Available
Etymology
carex: Latin name for a species of sedge, now applied to the whole group.
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.
CARDIA
Chromosome number
2n = c.60
Previous conservation statuses
2017 | Not Threatened | Qualifiers: SO
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 (110 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.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Carex diandra Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/carex-diandra/ (Date website was queried)