Eurasian water-milfoil

Myriophyllum spicatum L.

U.S. Nativity: Exotic
Habit: Aquatic

Synonym(s): spiked watermilfoil

Eurasian watermilfoil is a submersed aquatic plant that invades lakes, ponds, and other aquatic environments throughout the United States. The plants are rooted and the stems grow up to the water surface, usually reaching 3 to 10 ft. (0.9-3 m) in length, however they can be as much as 30 ft. (9.1 m) long. Eurasian watermilfoil forms dense mats of bright green, finely dissected, whorled leaves. The delicate leaflets give this plant a feathery appearance. Eurasian watermilfoil requires stagnant to slowly moving water and can tolerate brackish conditions. Once established the dense mats of leaves restrict light availability, leading to a decline in the diversity and abundance of native macrophytes. In addition, Eurasian watermilfoil displaces the native species of watermilfoil and reduces habitats for fish spawning and feeding. Eurasian watermilfoil is native to Europe, Asia, and northern Africa. It was accidentally introduced into the United States sometime between the late 1800s and 1940s.

Identification, Biology, Control and Management Resources

Biological Control of Invasive Plants in the Eastern United States - USDA Forest Service
Southeast Exotic Pest Plant Council Invasive Plant Manual - SE-EPPC
Plant Invaders of Mid-Atlantic Natural Areas - National Park Service and U.S. Fish and Wildlife Service
Weeds Gone Wild: Alien Plant Invaders of Natural Areas - Plant Conservation Alliance
Invasive Plant Atlas of New England - University of Connecticut
Global Invasive Species Database - Invasive Species Specialist Group
Images, Video and Information - University of Florida - Center for Aquatic and Invasive Plants
Fact Sheet - Ontarios Invading Species Awareness Program

EDDMapS Distribution: