Eurasian Watermilfoil | National Invasive Species Information Center

Eurasian watermilfoil, infestation; dense canopy on surface at Cayuga Lake (New York) - Photo by Robert L. Johnson; Cornell University

Scientific Name:

Myriophyllum spicatum L. (ITIS)

Common Name:

Eurasian watermilfoil, spiked watermilfoil

Native To:

Europe, Asia, and North Africa (Eiswerth et al. 2000)

Date of U.S. Introduction:

Exact date unknown; between the 1880s and the 1940s (Eiswerth et al. 2000)

Means of Introduction:

Unknown, possibly through the aquarium trade or transport of watercraft (Nichols and Shaw 1986)

Impact:

Crowds out native species (Smith and Barko 1990)

Spotlights

Spread the Word, Not the Weeds (Feb 22, 2021)

USDA. Blog.

Deceptively delicate and fragile in appearance, the Eurasian watermilfoil forms thick mats in shallow areas of a lake, quickly growing and spreading to block sunlight, killing off native aquatic plants that fish and other underwater species rely on for food and shelter. In North America, the plant threatens the diversity and abundance of native plants as well as the ecological balance of lakes and ponds, which in turn adversely affects recreational opportunities. If left unchecked, invasive watermilfoil will spread through a lake, or even to other lakes by transmission. An expert team of USDA Forest Service divers with invasive species and aquatics expertise is focused on rooting out the plant.

Distribution / Maps / Survey Status

Early Detection & Distribution Mapping System (EDDMapS) - Eurasian Water-milfoil

University of Georgia. Center for Invasive Species and Ecosystem Health.

Provides state, county, point and GIS data. Maps can be downloaded and shared.

Nonindigenous Aquatic Species Database: Point Map - Eurasian Watermilfoil

DOI. USGS. Wetland and Aquatic Research Center.

Provides detailed collection information as well as animated map.

Images

Google Images - Eurasian Watermilfoil

Google.

Invasive.org - Eurasian Water-milfoil

University of Georgia. Center for Invasive Species and Ecosystem Health.

Videos

Rapid Response Kit: Eurasian Water Milfoil

Google. YouTube; Wildlife Forever.

YouTube - How to Identify Eurasian Water-milfoil

Google. YouTube; Ontario Federation of Anglers and Hunters (Canada). Ontario's Invading Species Awareness Program.

Selected Resources

The section below contains highly relevant resources for this species, organized by source. Or, to display all related content view all resources for Eurasian Watermilfoil.

Council or Task Force

Fact Sheet: Eurasian Watermilfoil (Jan 2014) (PDF | 390 KB)

Alberta Invasive Species Council (Canada).

See also: Fact Sheets for more information about individual invasive species, including those listed as "Prohibited Noxious" and "Noxious" under the Alberta Weed Control Act

Invasive Plants of California's Wildlands - Myriophyllum spicatum

California Invasive Plant Council.

In online book: Bossard, C.C., J.M. Randall, and M.C. Hoshovsky (Editors). 2000. Invasive Plants of California's Wildlands. University of California Press. Berkeley, CA

Invasive Plants of Ohio: Fact Sheet 12 - Eurasian Water-milfoil (PDF | 368 KB)

Ohio Invasive Plants Council.

See also: Invasive Plants of Ohio for worst invasive plant species identified in Ohio's natural areas

Priority Species: Eurasian Watermilfoil

Washington State Recreation and Conservation Office. Washington Invasive Species Council.

Southeast Exotic Pest Plant Council Invasive Plant Manual - Eurasian Water-milfoil

Southeast Exotic Pest Plant Council.

Species of Concern Fact Sheet: Eurasian Water Milfoil

Aquatic Nuisance Species Task Force.

Partnership

Alaska Exotic Plants Information Clearinghouse (AKEPIC): Species Biography - Eurasian Watermilfoil (Feb 8, 2011) (PDF | 92 KB)

University of Alaska - Anchorage. Alaska Center for Conservation Science.

See also: Non-Native Plant Species List for additional factsheets (species biographies) and species risk assessment reports of non-native species present in Alaska and also non-native species currently not recorded in Alaska (potential invasives).

Global Invasive Species Database - Myriophyllum spicatum (aquatic plant)

IUCN. Species Survival Commission. Invasive Species Specialist Group.

Invaders Factsheet: Eurasian Watermilfoil

Ontario's Invading Species Awareness Program (Canada).

Invasive Plant Atlas of the United States - Eurasian Water-milfoil

University of Georgia. Center for Invasive Species and Ecosystem Health.

Invasive Species Compendium - Myriophyllum spicatum

CAB International.

NEANS Panel Online Guide - Eurasian Watermilfoil

Northeast Aquatic Nuisance Species Panel.

New York Invasive Species Information - Eurasian Watermilfoil

New York Invasive Species Clearinghouse.

Plantwise Technical Factsheet - Spiked Watermilfoil (Myriophyllum spicatum)

CABI. Plantwise Knowledge Bank.

Texas Invasives Database - Myriophyllum spicatum

TexasInvasives.org.

The Quiet Invasion: A Guide to Invasive Species of the Galveston Bay Area - Eurasian Watermilfoil

Texas Commission on Environmental Quality, Galveston Bay Estuary Program; Houston Advanced Research Center (HARC).

Weeds Australia - Eurasian Water Milfoil (Myriophyllum spicatum)

Centre for Invasive Species Solutions; Atlas of Living Australia; Australian Government. Department of Agriculture, Water and the Environment.

Federal Government

National Exotic Marine and Estuarine Species Information System (NEMESIS): Chesapeake Bay Introduced Species Database - Myriophyllum spicatum

Smithsonian Institution. Smithsonian Environmental Research Center. Marine Invasions Research Lab.

Nonindigenous Aquatic Species Database: Fact Sheet - Eurasian Watermilfoil

DOI. USGS. Wetland and Aquatic Research Center.

Provides distribution maps and collection information (State and County).

PLANTS Database - Eurasian Watermilfoil

USDA. NRCS. National Plant Data Center.

U.S. National Plant Germplasm System - Myriophyllum spicatum

USDA. ARS. National Genetic Resources Program. GRIN-Global.

International Government

NSW WeedWise: Eurasian water milfoil

New South Wales Department of Primary Industries (Australia).

Invasive Plants: Prohibited Invasive Plants - Eurasian Water Milfoil

Business Queensland (Australia).

State and Local Government

Environmental Fact Sheet: Eurasian Milfoil (2019) (PDF | 516 KB)

New Hampshire Department of Environmental Services.

See also: Publications - Invasive for more resources

Class B Noxious Weed: Eurasian Watermilfoil

Washington State Noxious Weed Control Board.

Eurasian Water Milfoil

Wisconsin Department of Natural Resources.

Invasive Plants in Pennsylvania: Eurasian Water-milfoil (PDF | 105 KB)

Pennsylvania Department of Conservation and Natural Resources.

See also: Invasive Plant Fact Sheets for plant species (trees, shrubs, vines, herbs and aquatic plants) that have impacted the state's natural lands

Noxious Weed Species - Eurasian Watermilfoil

Colorado Department of Agriculture. Conservation Services Division. Noxious Weed Program.

Academic

Invasive Plant Fact Sheet - Eurasian Water-milfoil (Nov 2011) (PDF | 138 KB)

University of Pennsylvania. The Pennsylvania Flora Project of Morris Arboretum.

See also: Invasive Plant Fact Sheets for additional invasive plants in Pennsylvania

AIS in Minnesota - Eurasian and Hybrid Watermilfoil

University of Minnesota. Minnesota Aquatic Invasive Species Research Center.

AQUAPLANT - Eurasian Watermilfoil

Texas A&M University. AgriLife Extension Service. Department of Wildlife and Fisheries Sciences.

Aquatic Plants and Algae: Eurasian Water Milfoil

Pennsylvania State University. Cooperative Extension.

Factsheet: Eurasian Watermilfoil

Pennsylvania State University. Pennsylvania Sea Grant.

See also: Aquatic Invasive Species: Resources for additional species information

Invasive Species Guide - Eurasian Watermilfoil

University of Wisconsin Sea Grant.

Maine Invasive Plants Bulletin: Eurasian Milfoil

University of Maine. Cooperative Extension.

See also: Maine Invasive Plants & Entire Series for entire series of 22 fact sheets and invasive plants brochure (available in HTML/PDF or for purchase)

Plant Profile: Myriophyllum spicatum

University of Florida. IFAS. Center for Aquatic and Invasive Plants.

Professional

Maine's Interactive Field Guide to Aquatic Invaders and Their Native Look Alikes - Eurasian Water-Milfoil

Lake Stewards of Maine.

Special Note: Formerly known as the Maine Volunteer Lake Monitoring Program.

Noxious Weed Information - Eurasian Watermilfoil

Colorado Weed Management Association.

Weed Identification - Eurasian Water Milfoil

Montana Weed Control Association.