Vascular – Exotic
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.
Grass-like yellowish-green sward-forming plant, with small prickly catkins (spikes) produced along the stems in spring.
Scattered throughout, common in high rainfall areas such as Westland and Southland.
Water body margins, swamps, damp waste places and low-lying areas.
Wetland plant indicator status rating
FACW: Facultative Wetland
Usually is a hydrophyte but occasionally found in uplands (non-wetlands).
Tufts ± dense. Stems variable, to 30 cm long and much > leaves, but often < leaves, erect or ± flaccid, smooth, subterete. Leaves 1.5-3 mm wide, channelled, dull yellow-green; ligule notched; sheaths almost white, becoming grey. Inflorescence of one terminal pedunculate male spike and 1-4 ± sessile, erect female spikes usually approximate at top of stem but often with a single female spike towards base of stem; subtending bracts > inflorescence, flaccid. Male spike to 2 cm × 2 mm; glumes light brown, ± 4 mm long, obtuse, light brown. Female spikes ± 1 cm × 5 mm; glumes < utricles, ovate, subacute, membranous, brown-tinged. Utricles ± 3 × 1 mm, glabrous, faintly nerved, inflated, yellow-green, obovoid, abruptly narrowed to a bifid beak to 1 mm long. Stigmas 3. Nut obovoid, trigonous.
Superficially similar to many Carex species with distinct male and female spikes. Perhaps closest to the related native C. flaviformis, distinguished by the female spike crowded beneath the male spike, not distant as with C. demissa).
Seed dispersed by contaminated machinery or waterfowl.
Europe, eastern Canada
Reason for introduction
Unknown, seed or soil contaminant.
Not controlled in New Zealand.
carex: Latin name for a species of sedge, now applied to the whole group.
Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA). Features description from Healy and Edgar (1980).
References and further reading
Champion et al (2012). Freshwater Pests of New Zealand. NIWA publication. http://www.niwa.co.nz/freshwater-and-estuaries/management-tools/identification-guides-and-fact-sheets/freshwater-pest-species
Johnson PN, Brooke PA (1989). Wetland plants in New Zealand. DSIR Field Guide, DSIR Publishing, Wellington. 319pp.