Manchurian wild rice

Manchurian wild rice is a giant perennial grass that can grow up to four metres tall.

Description

• Leaves are erect, 2.5 metres long, harsh, dull grey-green, with stout midribs. They make loud rustling sounds in the wind.

• Flowerheads are purple/brown, 60cm long, appearing between November-December

• Rhizomes are up to five metres long and roots are fibrous.

• Seeds and rhizome fragments are dispersed by water, animals, machinery, and fishing equipment.

• Habitats include freshwater and saline water body margins, wetlands, tidal flats, pasture, and ditches.

What you need to know

Manchurian wild rice forms dense clumps, displacing native vegetation and altering habitat structure. It displaces valuable pasture species, clogs waterways, and exacerbates flooding.

Management approach

Manchurian wild rice is declared an unwanted organism by the Ministry for Primary Industries (MPI) because it is capable of causing harm to the natural environment, physical resources or human health in Aotearoa/New Zealand.

These species pose a high risk to our environment, economy, recreation, and cultural values.

Rules

Any species declared a pest cannot be sold or be in a place where plants are being sold. Pest plants cannot be propagated, bred, multiplied, communicated, released, caused to be released, or otherwise spread.

Control

Do not attempt to undertake control of Manchurian wild rice yourself. Report sightings to the MPI on Exotic Pest Hotline at 0800 80 99 66 or the online reporting form.