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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Flower(s); Inflorescence
Leslie J. Mehrhoff, University of Connecticut,

Plant(s); Native to Africa, and Europe, invades lakes, ponds, and other water bodies throughout the United States.
Alison Fox, University of Florida,
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Leslie J. Mehrhoff, University of Connecticut,

Plant(s); a submersed aquatic plant at Cornell University Research Ponds
Robert L. Johnson, Cornell University,
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Steve Hurst, USDA NRCS PLANTS Database,
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Diagram or Graphic; Britton, N.L., and A. Brown. 1913. Illustrated flora of the northern states and Canada. Vol. 2: 614.
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Invasive Reference(s):

Check for most current lists.
  • Alabama - Noxious Weed Law
  • Alabama - IPC List
  • California - Invasive Plant Inventory
  • Colorado - Noxious Weed Law
  • Connecticut - Noxious Weed Law
  • Florida - EPPC list
  • Georgia - EPPC list
  • Maine - Noxious Weed Law
  • Massachusetts - Noxious Weed Law
  • Montana - Noxious Weed Law
  • New Mexico - Noxious Weed Law
  • Nevada - Noxious Weed Law
  • North Carolina - Noxious Weed Law
  • Oregon - Noxious Weed Law
  • Rhode Island - Noxious Weed Law
  • South Carolina - Noxious Weed Law
  • South Dakota - Noxious Weed Law
  • Tennessee - EPPC List
  • Texas - Noxious Weed Law
  • Texas - Invasive Plant List
  • Vermont - Noxious Weed Law
  • Virginia - Invasive Alien Plant Species
  • Washington - Noxious Weed Law
  • Mid-Atlantic - EPPC List
  • Invasive Plants: Western North America
  • Invasive Plants of the Upper Midwest
  • Invasive Plant Atlas of New England
  • Invasive Plant Atlas of the Mid-South

External Links

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USDA Forest Service Bugwood University of Georgia