Species Information

Eurasian watermilfoil Eurasian watermilfoil

Eurasian watermilfoil
Eurasian watermilfoil
Myriophyllum spicatum

History

• Accidentally introduced to northeastern United States sometime between the late 1800s and 1940s


Characteristics

• Rooted, submersed, perennial, aquatic plant
• Narrow, reddish-brown stems grow to the water surface, extending 3-10 ft (1-3 m) or longer
• Forms dense beds
• Feather-like leaves with blunt ends, grouped in whorls around stem
• Small flowers project 2-4 in (5-10 cm) above the water surface


Habitat

• Lakes, ponds, slow-moving streams, reservoirs, and estuaries
• Depths greater than 3 ft (0.9 m)
• Tolerates brackish water
• Thrives in highly disturbed lake beds, lakes receiving nitrogen and phosphorus-laden runoff, and heavily used lakes


Distribution in Northeast

• Quebec and most of the U.S. 
• Native to Europe, Asia, northern Africa


Impacts

• Highly aggressive, nuisance species
• Can form dense mats that shade and crowd out native plants
• Degrades habitats used by fish for spawning and feeding
• Thick growth can impair recreational uses of waterways including boating, swimming, and fishing
• Yellow-green, matted vegetation on milfoil-dominated lakes creates perception that lake is “infested” or “dead"
• Control efforts cost millions of dollars annually; $500,000 per year in New York state alone


Eurasian watermilfoil underwater
Eurasian watermilfoil
Eurasian watermilfoil
RIDEM
Eurasian watermilfoil
Hahnel
Eurasian watermilfoil
Eurasian watermilfoil
Hahnel
Eurasian watermilfoil
Eurasian watermilfoil
Hahnel
Eurasian watermilfoil
Eurasian watermilfoil (Myriophyllum spicatum)
Alison Fox, University of Florida
Eurasian watermilfoil underwater
Hahnel
Eurasian watermilfoil
Hahnel