Cyperus eragrostis


Cyperus: From the ancient Greek name for sedge, kypeiros

Common Name(s)

umbrella sedge


Cyperus eragrostis Lam.



Brief Description

Tufted leafy sedge, with triangular stems up to 90 cm tall, leaves arranged in threes, with a group of 5 to 7 green round flowerheads, each made up of broad flattened flower spikes, with 5 to 8 long grass-like leaves immediately under this, at the end of flower stalk.

Flora Category

Vascular - Exotic

NVS Species 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.

Structural Class



Scattered throughout both islands, locally abundant.


Wet areas such as the banks of rivers and streams, swamps, ditches.


Rhizome short, thick, woody. Stems 25-90 cm high, stout, obtusely trigonous, smooth, leafy and ± thickened at base. Leaves usually < stems, 4-8 mm wide, flat, margins finely serrate; sheaths dark purple-brown. Involucral bracts 5-8, leaf like, unequal, often very much > inflorescence. Inflorescence a compound umbel, rather variable in size; rays 5-7- (9), of unequal length, each with a dense pale green to yellow-green globose or hemispherical spike at tip, 1-2 cm diam. Spikelets many, densely crowded, much compressed, ± 5-12 ×3 mm, ovoid-oblong, subacute. Glumes many, ± 2 mm long, densely imbricate, ovate, membranous, cells very distinct, whitish-cream to light brown, 1-distinct lateral nerve on each side, keel green, tip slightly recurved. Stamen 1. Style-branches 3. Nut ± ½ length of glume, trigonous, obovoid brown (Healy and Edgar, 1980).

Similar Taxa

Similar to other Cyperus species, distinguished from the other species by the globular yellow-green flowerheads and basal leaves.


Summer to autumn

Flower Colours



Summer to autumn

Year Naturalised



North and South America

Reason for Introduction

Unknown, possibly ornamental plant, 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.


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. 

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.

This page last updated on 30 Jul 2014