Eurasion Milfoil

Impact – The fast-growing shoots and extensive canopy obstructs recreation and navigation. The decomposition of plant mass at the end of the season results in Nitrogen and Phosphorous loading. It is found throughout the Adirondacks. There is also a variable -leaf milfoil (invasive). It is next to impossible to eradicate once it is established.

What It Is – A well-adapted hardy perennial plant that produces dense water canopies that shade out native plants. Infestations result in decreased oxygen levels and elevate pH altering eco-systems. It spreads by primarily by fragmentation such as when boats travel thru beds and may be transported by boats from water body to water body.

How to Identify – Spaghetti like stems have leaves arranged in three to five whorls around the stem and can grow in waters as deep as 15 ft. Leaves are divided like a feather with about 12-20 pairs of thread-like leaflets. The tips of EM whorls often have a blunt, snipped-off appearance. Whorls can be widely spaced, up to 1 + inches or more. Individual stems may branch several times as they reach the surface. A flower spike emerges in late summer sticking out of the water. Plants will go limp when removed from the water. Note- Look-alikes- there are up to 7 native milfoils and SL does have some which can be difficult to distinguish. EM usually has more than 12 pair of leaflets whereas Northern Water-milfoil (native) has typically 5-12. Native milfoils have whorls spaced much closer together. Left 2 pics- EM, right- Variable.

Control – Contact ESSLA if you suspect this invasive with location. ESSLA organized an active “scout“program with volunteers that survey the lake every summer, reporting findings to professional hired dive companies that hand harvest this along with curly-leaf pondweed (invasive). The good news is that while we are not able to eliminate this noxious weed, we have it under control and are in a maintenance mode. If you would like to volunteer, contact us at ESSLA.org.