Eurasian watermilfoil

Haloragales > Haloragaceae > Myriophyllum spicatum L.
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

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Number:5240027
Description: Foliage;
Photographer:Richard Old, XID Services, Inc.
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Number:5240028
Description: Foliage;
Photographer:Richard Old, XID Services, Inc.
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Number:5273022
Description: Flower(s); Inflorescence
Photographer:Leslie J. Mehrhoff, University of Connecticut
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Number:1624031
Description: Plant(s); Native to Africa, and Europe, invades lakes, ponds, and other water bodies throughout the United States.
Photographer:Alison Fox, University of Florida
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Number:5273023
Description: Infestation;
Photographer:Leslie J. Mehrhoff, University of Connecticut
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Number:0002001
Description: Plant(s); a submersed aquatic plant at Cornell University Research Ponds
Photographer:Robert L. Johnson, Cornell University
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Number:5308029
Description: Seed(s);
Photographer:Steve Hurst, USDA NRCS PLANTS Database
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Number:5308027
Description: Diagram or Graphic; Britton, N.L., and A. Brown. 1913. Illustrated flora of the northern states and Canada. Vol. 2: 614.
Photographer:USDA PLANTS Database, USDA NRCS PLANTS Database
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External Links

Invasive Reference(s)

Subject Reference(s)

  • USDA, NRCS. 2001. The PLANTS Database, Version 3.1, National Plant Data Center, Baton Rouge, LA 70874-4490 USA. - http://plants.usda.gov/