Marshwort

Common name: Marshwort
Botanical name: Nymphoides geminata
Management programme: Exclusion

Where is it originally from?

Marshwort originates from Victoria and New South Wales, Australia.

Why is it a pest?

Marshwort colonises shallow waters, rapidly forming dense mats which cover waterways, interfere with drainage and recreational activities, and outcompetes native species. It is easily spread by fragments moved by machinery, boats, fishing gear and water currents.

Where is it found?

• Grows from long, creeping stems that extend just under the water surface for several metres.
• Found in ponds, lakes, wetlands, swamps and drains.
• Is a freshwater plant, preferring still or slow flowing shallow water along the edges. Can also survive in damp mud.

What does it look like?

• Marshwort is a water lily-like aquatic plant with bright green heart shaped floating leaves. The leaves have pinkish undersides and grow up to 10cm across.
• Flowers between November and April are bright yellow, with five fringed petals.
• The long branched stems float just below the water surface, with roots suspended in deeper water.

What are the rules?

Exclusion

Exclusion pests are not known to be present/established in the Bay of Plenty region. The Bay of Plenty Regional Council is responsible for managing new incursions into the region. Action may be required from landowners or occupiers to support a control operation.

Please contact the Bay of Plenty Regional Council if you think you have found Marshwort.

How do you get rid of it?

If you think you have found Marshwort please contact the Bay of Plenty Regional Council for advice.