Clasped Pondweed

Africa, Australia, Eurasia, North America

General description

Perennial submerged aquatic herb. Roots and rhizomes are slender. Stems are < 2 m long, trailing and leafy. Leaves are ovate, translucent, alternate and basally wrapped around the stem. Flowers are small, green and borne on spikes in November – January. Fruit is olive green and smooth.

What you need to know

To help protect our environment:

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

Flowing or still freshwater bodies, lakes, streams, ponds, estuaries.

Sets seed. Vegetative spread from stem fragments. Seeds and stem fragments dispersed by water and possibly birds. Human-mediated dispersal through disposal of aquarium waste and movement of contaminated boats, trailers, machinery and equipment.

Can form dense infestations, altering natural habitat structure and blocking waterways. May hybridise with native Potamogeton spp.

Site Management

Very difficult to control once established. Requires an aquatic pest plant control operator. Contact Auckland Council for control options.

Recommended approaches

Physical control

Method: Dig out

Plant parts requiring disposal: All parts

Disposal options: Remove to greenwaste or landfill if practical


Biocontrol is currently not available for this species.

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

Search tags

RPMP status

National Pest Plant Accord Species
Clasped pondweed - Main species image