Cyperus alternifolius subsp. flabelliformis
Cyperus flabelliformis Rottb.; Cyperus involucratus Rottb.
Vascular – Exotic
Distinctive sedge with almost rounded stems up to 80 cm, with many leaves at the top of each otherwise leafless stem, underneath an open flower head with many stalked clusters of flattened green spikes
Scattered in many parts of North island (usually close to habitation) and also in Christchurch.
Margins of water bodies and in drains.
Wetland plant indicator status rating
FACW: Facultative Wetland
Usually is a hydrophyte but occasionally found in uplands (non-wetlands).
Rhizome short, stout. Stems to 60 cm high, stout, subterete. Leaves reduced to closely appressed, very pale brown basal sheaths. Involucral bracts many, ± equal, to 25 cm × 10 mm, > inflorescence, tips shortly acuminate. Inflorescence a compound umbel; rays many, to 8 cm long. Spikelets in small clusters at tips of rays, ± 4 × 2 mm, ovoid to linear-oblong, compressed, shining. Glumes densely imbricate, ± 2 mm long, ovate, obtuse, hyaline, white to light brown with green keel. Stamens 3. Style-branches 3. Nut ± ⅓ length of glume, trigonous, ovoid-ellipsoid, brown (Healy and Edgar, 1980).
Similar to a small papyrus (and sometimes sold under that name), differing in the presence of persistent leaf-like bracts and upright flower stalks in Cyperus involucratus, rather than deciduous bracts and filamentous, drooping, mostly sterile flower stalks of papyrus.
Summer to autumn
Summer to autumn
Deliberate planting or garden waste dumpings.
Reason for introduction
Not controlled in New Zealand.
cyperus: From the ancient Greek name for sedge, kypeiros
Prepared by Paul Champion and Deborah Hofstra (NIWA). Features description from Edgar and Healy (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.
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.