Species

Carex divulsa

Etymology

Carex: Latin name for a species of sedge, now applied to the whole group.

Common Name(s)

grey sedge

Authority

Carex divulsa Stokes

Family

Cyperaceae

Brief Description

Dense grass-like, dark green tussock, up to 50 cm tall, with longer flower spikes, the spikes are made up of small groups of small green flowers on a thin arching stem. (Despite its common name, plants in NZ are mid-green to yellow green, not grey.)

Flora Category

Vascular - Exotic

NVS Species Code

CARDIV

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

Sedges

Distribution

Scattered throughout the North Island and Nelson, Marlborough and Canterbury; Chatham Islands.

Habitat

Widespread from the coast to subalpine situations. Usually found as a pasture and lawn weed with a distinct preference for calcareous or other base-rich substrates. Will colonise forest especially forest margins and gaps. A serious weed in native vegetation.

Features

Dense, dark-green to yellow-green, deeply rooted grass-like tussock-forming sedge. Rhizome thick, short, ascending with dark brown scales soon becoming fibrous. Stems 0.15-1.8 m high, slender and wiry, 3-angled, scabrid on angles. Leaves 2-3 mm wide, < stems, flat to channelled, rather harshly scabrid, sheaths dull, light creamy-brown. Inflorescence 50-120 mm long, often with 1-2 very short branches at base; spikes ± 10, sessile, light green, distant below, 3-5 uppermost more crowded; bracts filiform. Spikes few-flowered, androgynous, male flowers at top. Glumes much < utricles, ovate, acuminate, colourless-hyaline with a green midrib. Utricles 4-5 × ± 2 mm, ovate, plano-convex, nerveless, light brown, tapering to a short bifid beak with scabrid margins, stipe minute. Stigmas 2. Nut obovoid, biconvex.

Similar Taxa

The mixed-sex flower spikes resemble those of the native C. virgata and C. secta, but C. divulsa is much smaller and the leaf margins are not cutting.

Flowering

Late spring

Flower Colours

Brown,Green

Fruiting

Summer

Year Naturalised

1883

Origin

Europe, North Asia, North Africa

Reason for Introduction

Ornamental plant

Control Techniques

Not difficult to hand-pull - take the plants (or at least the seed heads) away and destroy them. Not often controlled in New Zealand.

Life Cycle and Dispersal

Long-lived perennial sedge. Seed dispersed by contaminated machinery or garden discards.

Tolerances

Cold and drought tolerant - can tolerate a wide range of soils types

Attribution

Factsheet prepared by Paul Champion and Deborah Hofstra (NIWA).

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.

Healy, A.J.; Edgar, E.  (1980). Flora of New Zealand, Volume III.  Adventive Cyperaceous, Petalous and Spathaceous Monocotyledons.  Government Printer, Wellington.  220pp.

This page last updated on 16 Jun 2019