Carex calcis


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

Common Name(s)


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 - Sparse


2012 - RR, Sp


Carex calcis K.A.Ford



Flora Category

Vascular - Native

Structural Class



None (first described in 2007)


Endemic. New Zealand: South Island. North-West Nelson from about the Garibaldi Ridge south to the Matiri Plateau


Upper montane to alpine. Exclusive to on soils derived from weathered limestone and calcareous mudstone/siltstone Carex calcis is a plant of open shrubland and Chionochloa tussock grassland. It is also common in the grasslands and shrublands developed on colluvial deposits at the base and lower slopes of the escarpments and slips scars.


Perennial herb, tufts stout, rigid, spreading; occasionally shortly rhizomatous. Culms (40–)150–300(–575) × 1.5–2.0 mm, stout, ascending to spreading, trigonous, striated, smooth, rarely scabrid above, longer than, similar to, or shorter than leaves when mature. Leaves (115–)150–300(–380) × 2.5–6.0 mm; leaf sheaths loose, dull brown, becoming stringy with age, nerves distinct; leaf blades channelled, occasionally double-folded, stiff, green; leaf margins and keel thickened, scabrid; apex trigonous, scabrid, acuminate. Inflorescence of 4–6(–7) densely flowered separate male and female spikes, brown, erect, borne singly at nodes, mostly sessile, closely contiguous towards the top of the culm, often lower spike remote and sometimes on a short peduncle; terminal spike male, 7.0–30 × 2.0–3.7 mm, clavate, cylindrical, brown, occasionally distal part female; remaining spikes female 6.0–35 × 5.0–7.0 mm, stout, oblong, cylindrical, brown, sometimes with a few terminal male flowers above, particularly on upper female spike. Lowermost inflorescence bract leaflike, (60–)100–200(–350) × 2.5–5.5 mm, longer than inflorescence. Male glumes 4.0–6.4 × 1.6–2.0 mm long, speckled brown, obovate, concavo-convex, subcoriaceous, mid-region 3-veined, green fading to white at maturity; margins membranous, entire, scabrid towards apex; apex emarginate, midvein often failing, sometimes mid-vein excurrent then apex acute or shortly awned, awn scabrid. Female glumes 2.1–4.0 × 1.6–2.2 mm, shorter or similar length to utricles, speckled brown, ovate, concavo-convex, subcoriaceous, mid-region green fading to white; margins membranous, fimbriate towards apex; apex acute sometimes shortly awned. Stamens 3, anthers 1.5–2.5 mm long. Utricles 2.5–3.7 × 1.2–2.3 mm, spreading at maturity, trigonous to subtrigonous, obovate to elliptic, sometimes slightly winged, abruptly narrowed to a distinct white beak, speckled brown to dark brown above (except for beak), usually with distinct broad, pale nerves; beak 0.4–0.5(–0.7) mm long, bidentate, white, margins occasionally scabrid; orifice slightly oblique, scabrid. Stigmas 3, 0.8–1.2 mm long. Nut 1.3–1.6 × 0.9–1.2 mm, trigonous, brown.

Similar Taxa

Carex calcis is perhaps most closely allied to C. dolomitica Heenan et de Lange, from which it differs by the loose brown and often shredding sheaths; female spikes cylindrical and brown; and by the utricles which are 2.5–3.7 × 1.2–2.3 mm, speckled brown to dark-brown above, with a white beak, obovate-elliptic in shape, the apex narrowed abruptly to a beak; and trigonous to subtrigonous to cross-section. Carex dolomitica differs by the tufts bearing clasping dark brown sheaths (these rarely shredding); female spikes which are tapered, dark brown or red; utricles which are 3.2–4.2 × 1.3–1.9 mm, shiny black above, with a red or white beak; broad-ovoid to ovoid, elliptic or narrow-elliptic, tapering to a beak, and plano-convex to subtrigonous in cross-section




January - March

Propagation Technique

Easily grown from fresh seed and by division of established plants. Prefers full sun in a permanently moist but free draining soil enriched with lime. Dislikes humidity.


Not Threatened - but biologically sparse over its entire range. Previously regarded (as Carex (b) (AK 232856; Matiri)) as Sparse in de Lange et al. (2004)

Chromosome No.

2n = c.68

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


Fact Sheet by P.J. de Lange (1 January 2008). Description from Ford (2007)

References and further reading

de Lange et al., 2004, Threatened and uncommon plants of New Zealand, New Zealand Journal of Botany 42: 45-76.

Ford, K.A. 2007: Carex (Cyperaceae) - two new species from the calcareous mountains of North-West Nelson, New Zealand. New Zealand Journal of Botany 45: 721-730.

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 18 Jun 2015