Californian Bulrush

Also known as:
Californian Bullrush
North America

General description

Large aquatic perennial sedge, rounded or triangular bright-green stems, to 3 m tall. Leaves absent, it has papery thin sheathing bracts at the base of the stem, with small groups of flowers on drooping stalks near the tip. Grows from dense woody rhizomes buried in bottom sediments, usually in tidal reaches of large rivers like the Waikato and Northern Wairoa.

Marginal aquatic (freshwater-brackish) plant.

Reproduction through seed and through vegetative spread from rhizomes. Seed is bird and water dispersed. Vegetative spread happens through detachment and deliberate plantings

Forms tall dense beds that colonise mobile sand deposits and river margins, where it may displace smaller native species. Can cause erosion of riverbanks by colonising and infilling the inside bank, thereby increasing flow stress on the outside bank.

Site management

Recommended approaches

1. Mechanical removal at small sites.
2. For chemical control options contact the ARC Biosecurity team on 09 366 2000 or

Caution: when using any herbicide or pesticide PLEASE READ THE LABEL THOROUGHLY to ensure that all instructions and safety requirements are followed.

RPMS status

Surveillance - Whole Region
National Pest Plant Accord species - nationwide
Californian bulrush - Main species image