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Eurasian Watermilfoil

Eurasia and Africa

General description

Perennial submerged rhizomatous aquatic herb. Stems are long, branching and smooth. Leaves are soft, pinnate, feather-like and borne in whorls of four. Flowers are small, yellow and borne on emergent spike. Fruits contain four seeds.

What you need to know

To help protect our environment:

  • You must not breed, distribute, release or sell Eurasian watermilfoil. As Eurasian watermilfoil is an Unwanted Organism, these restrictions apply within the Auckland region and across the whole of New Zealand.

Rivers, lakes, streams, reservoirs, ponds, drains, tidal creeks, bays.

Sets seed. Vegetative spread from runners and stem fragments. Seed and stem fragments dispersed by water. Human-mediated dispersal through movement of contaminated boats, equipment and machinery.

Forms dense mats, outcompeting native plants and altering habitat structure. Impedes drainage and recreational activities.

Site Management

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.

Similar species

parrots feather
Myriophyllum aquaticum

Each Eurasian watermilfoil leaf generally has 12 or more leaflet pairs and this feature can be used about 70 percent of the time to distinguish Eurasian watermilfoil from other milfoil species.

Ceratophyllum demersum

Hornwort has forked leaves as opposed to the pinnate leaves of E. water milfoil.

Search tags

RPMP status

Unwanted Organism
Eurasian watermilfoil - Main species image