Vascular – Native
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.
2n = c.60
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley.
2012 | Not Threatened
Previous conservation statuses
2009 | Not Threatened
2004 | Not Threatened
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.
Coastal to subalpine in open, moderately fertile to mid oligotrophic wetlands developed on river flats, within forest or in short or tall-tussock grasslands.
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.
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.
October - December
December - May
Nuts surrounded by inflated utricles are dispersed by granivory and wind (Thorsen et al., 2009).
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.
carex: Latin name for a species of sedge, now applied to the whole group.
Where To Buy
Not Commercially Available
Fact Sheet prepared for NZPCN by P.J. de Lange (110 August 2006). 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
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)