Identifying Milfoil
Watermilfoil (or milfoil) occurs in patches that tend to crowd out all other growth. Feather-like leaves are finely dissected to midrib and whorled around the hollow stem at intervals along the entire length of the plant.

Milfoil stays submerged except for a stalk of tiny flowers, which can extend above the surface. All milfoil species are easily identified as a group because of their distinctive feather-like leaves, but individual species are hard to differentiate from one another. DNA or pigment analysis may be necessary to tell individual milfoil species apart.
Where To Find Milfoil