What is Eurasian Water Milfoil (Myriophyllum spicatum L.)?
EWM is an “evergreen” perennial aquatic plant that grows submersed in water as deep as light will penetrate. In our clear waters, it grows faster and at greater depths. The only part of the plant that grows out of the water is the short flower stalk late in the summer. The submersed shoots form a dense offensive canopy at the water’s surface. In the winter, green stems may be found under the ice, although with little metabolic activity. EWM was first reported in the United States in the 1940’s in Chesapeake Bay and spread rapidly. The current EWM distribution includes 45 of the 50 states and three Canadian providences. EWM is possibly the most widespread nonnative aquatic plant in North America. What does EWM look like? EWM has the following recognizable characteristics: • Delicate feather-like leaves. Leaflets are mostly the same length. • Leaves are usually limp when out of the water. • Leaves arranged in whorls (circles) of three to five around the stem. • Usually twelve to twenty-o
