Eurasian Watermilfoil

Myriophyllum spicatum L.

Photo: Maine DEP. Drawing: University of Florida/IFAS Center for Aquatic and Invasive Plants.


Eurasian water-milfoil is a submerged plant with feather-like whorled leaves. It grows in extremely large dense mats in depths up to 15 feet. This plant produces a flower spike that emerges from the water's surface.

General Information

Eurasian water-milfoil, a native plant of Europe and Asia, is a serious threat to lakes and ponds throughout the United States. This species of water-milfoil was first discovered in a small pond in Maine in 2003. It is also found in nearby Massachusetts, Vermont, New Hampshire, Connecticut, and the Canadian Provinces.

Once introduced into a lake, Eurasian water-milfoil is virtually impossible to eradicate. It grows rapidly and aggressively, reproducing primarily through fragmentation. The introduction of one single fragment of this plant can result in the infestation of an entire lake.

The impacts of an infestation have the potential to be devastating. Dense mats of Eurasian water-milfoil impair boating, fishing, and swimming. Reduced lake water quality is another concern along with the potential decline of shorefront property values.