Carex leporina
Common names
oval sedge
Biostatus
Exotic
Category
Vascular
Structural class
Sedges
Simplified description
Dense pale green grass-like tufts or mat-like swards up to 1 m tall, with slightly taller flower stem bearing brown oval heads near the tip.
Flower colours
Brown, Green
Detailed description
Dense tufts; rhizome short. Stems 20–60–(120) cm tall, 3-angled, scabrid just below inflorescence. Leaves 1.5–3.5 mm wide, usually < stems, ± flat, ± soft, bright green, sheaths light brown. Inflorescence a compact ovoid head 2.5–4–(6) cm long, of 3–5–(11) approximate, sessile, light green to light brown spikes; bracts glume-like and inconspicuous or > inflorescence and ± setaceous. Spikes androgynous, male flowers at base. Glumes = or slightly < utricles, light brown with paler green to brown midrib, acute. Utricles 4–4.5 × ± 2 mm, ovoid, plano-convex, distinctly nerved, with winged margins almost covered by glumes, scabrid towards the tapered beak of ± 1 mm long. Stigmas 2. Nut plano-convex, ± oblong.
Similar taxa
Two other Carex spp. have oval spikes (C. scoparia and C. longii). Both these species have glumes shorter than the utricle, so C. leporina spikes appear less compact (see comparison with C. scoparia in photo).
Distribution
Locally common throughout New Zealand.
Habitat
Wide variety of wet habitats from lowland to subalpine, especially disturbed habitats, but also a problem weed in short turf wetland where it can completely displace indigenous vegetation.
Conservation status
Not applicable
Detailed taxonomy
Family
Cyperaceae
Synonyms
Carex ovalis Gooden.
Ecology
Flowering
Late spring to early summer
Fruiting
Summer to autumn
Year naturalised
1879
Origin
Europe, Asia, North Africa
Reason for introduction
Unknown, seed or soil contaminant.
Control techniques
Can be controlled manually, mechanically or herbicidally depending on situation.
Life cycle and dispersal
Seed dispersed by contaminated machinery or waterfowl.
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]
FACW: Facultative Wetland
Usually is a hydrophyte but occasionally found in uplands (non-wetlands).
Other information
Etymology
carex: Latin name for a species of sedge, now applied to the whole group.
Environmental Weed (2024)
This plant is named in a list of 386 environmental weeds in New Zealand 2024 prepared by DOC. 759 candidate species were considered for inclusion on this new comprehensive list of environmental weeds in New Zealand. The species considered were drawn from published lists of weed species, lists of plants that must be reported or managed by law if observed, existing national and regional programmes and agreements for pest management, and species already managed by the Department of Conservation (DOC). Candidate species were then assessed to see if they were fully naturalised and whether they have more than minor impacts in natural ecosystems. Read the full report here.
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.
CARLEP
Referencing and citations
References and further reading
Champion P. et al. 2020. Freshwater Invasive Species of New Zealand 2020. NIWA publication. https://docs.niwa.co.nz/library/public/FreInSpec.pdf
Healy AJ, Edgar E. 1980. Flora of New Zealand, Volume III. Adventive Cyperaceous, Petalous and Spathaceous Monocotyledons. Government Printer, Wellington, NZ. 220 p.
Johnson PN, Brooke PA. 1989. Wetland plants in New Zealand. DSIR Field Guide, DSIR Publishing, Wellington, NZ. 319 p.
Attribution
Prepared by Paul Champion and Deborah Hofstra (NIWA). Features description from Healy and Edgar (1980).
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.