Variable Leaf Watermilfoil

Other Common Names: red myrio

(Myriophyllum heterophyllum)


Variable leaf watermilfoil has thick reddish stems and can have submersed and emersed leaves that are feathery, limp, and deeply divided.


Variable leaf watermilfoil has reddish stems that are thick, round, and can grow several feet long. Submersed leaves are feathery, limp, and deeply divided. They can grow up to two inches long and one inch wide and are spaced out on the stem about three-fourths of an inch. Emersed leaves are rigid, sword or elliptical shaped, and usually grow one half to three-fourths of an inch long and five-hundredths of an inch wide. The emersed parts of this plant stand about four inches above the water’s surface. Both types of leaves grow in whorls of four to six around the stem. Tiny brownish red flowers with four petals and jagged edges grow on the stems at the base of the leaves in whorls of four to six.


Variable leaf watermilfoil can grow in waters 12 feet deep or more. In deep waters, the plant may have only submersed leaves. This is a native plant, but it is an aggressive invader because of its remarkable growth rate.


Variable leaf watermilfoil can be found in the eastern two-thirds of the United States.


fragments, roots