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.
Very dense green grass-like tufts up to 1 m tall, leaves conspicuously arranged in three planes, with slightly taller flower stem bearing pale green or yellow-brown oval heads near the tip.
Scattered throughout the North island, absent from most eastern areas.
Swamps and lake margins.
Wetland plant indicator status rating
FACW: Facultative Wetland
Usually is a hydrophyte but occasionally found in uplands (non-wetlands).
Very dense leafy tufts up to 90 cm high. Stems slender, sharply 3-angled, scabrid on margins below inflorescence. Leaves < stems, 2-3 mm wide, ± flat. Inflorescence 2-6 cm long, of 4-12 very clearly defined sessile spikes aggregated into an oblong or linear-oblong head; one or two lower spikes with small inconspicuous setaceous bracts < inflorescence. Spikes androgynous, male flowers at base, oblong or ovoid-oblong, tapering or rounded at apex. Glumes < utricles, lanceolate, acute, narrower than utricles at tip, light brown or white-hyaline, midrib green. Utricles ± 4 × 1-1.5 mm, lanceolate to narrow ovate-lanceolate, flat, faintly nerved on each side, greenish to brownish, ± narrowly winged throughout, minutely scabrid on margins of upper half, tapering to a beak ± 1 mm long. Stigmas 2. Nut ovoid-oblong.
Two other Carex spp. have oval spikes (C. ovalis and C. longii). C. scoparia is more robust than the other species and usually has more spikes per culm (see comparison with C. ovalis in photo).
Late spring to early summer
Summer to autumn
Seed dispersed by contaminated machinery or waterfowl.
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
Healy, A.J.; Edgar, E. (1980). Flora of New Zealand, Volume III. Adventive Cyperaceous, Petalous and Spathaceous Monocotyledons. Government Printer, Wellington. 220pp.
Johnson PN, Brooke PA (1989). Wetland plants in New Zealand. DSIR Field Guide, DSIR Publishing, Wellington. 319pp.
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