Zizania latifolia

Manchurian wild rice

Family: Poaceae

Origin: Asia

Manchurian Wild Rice with flower head.
A tall grass that has leaves up to 3m long. Forms dense mats of rhizomes underground.
Photo credit: Greg Hoskins

Regional Pest Management Plan (RPMP) status

  • Notifiable organism
  • National Pest Plant Accord Species

View more about the RPMP statuses

General description

Rhizomatous, mat-forming perennial grass < 3 m tall. Leaves are erect, < 2.5 m long, harsh, dull grey-green and pointed, with stout midribs. Flowers are borne in < 60 cm long, purple/brown flowerheads in November – December.

What you need to know

To help protect our environment:

  • You must not breed, distribute, release or sell Manchurian wild rice. As Manchurian wild rice is a National Pest Plant Accord species, these restrictions apply within the Auckland region and across the whole of New Zealand.

If you see Manchurian wild rice anywhere within the Auckland region, you must report it to Auckland Council at pestfree@aucklandcouncil.govt.nz.

Habitats

Freshwater and saline water body margins, wetlands, tidal flats, pasture, ditches.

Dispersal

Seeds dispersed by water, wind and possibly birds. Vegetative spread from rhizome fragments. Human-mediated dispersal through movement of contaminated soil, boats, equipment, machinery and livestock.

Impact on environment

Forms dense clumps, displacing native vegetation and altering habitat structure. Displaces valuable pasture species, clogs waterways and exacerbates flooding.

Control

Recommended approaches

Do not attempt to undertake control of this species. Please report to Auckland Council.

;

Caution: When using any herbicide or pesticide please read the label thoroughly to ensure that all instructions and safety requirements are followed.

Manchurian Wild Rice with flower head.
A tall grass that has leaves up to 3m long. Forms dense mats of rhizomes underground.
Photo credit: Greg Hoskins
Manchurian Wild Rice plant in wetland.
This is a difficult plant to control. Can take over entire river banks once it is established.
Photo credit: Greg Hoskins