Variable-leaf Milfoil is a submersed, rooted, perennial, aquatic plant that is native to the eastern United States. It has both underwater and emergent leaves with dark red to reddish brown stems. The submerged part of the plant has feather-like leaves, arranged in whorls of four to six around the stem. It usually grows in water up to 6 feet deep, but occasionally grows in deeper water.

Variable-leaf Milfoil flowers from the spring through fall and is a very aggressive invader. Control with aquatic herbicides is best achieved when plants are young.