Common Name(s): Variable-leaf milfoil, Two-leaf water-milfoil
Native to Florida
For brief control information, see Efficacy of Herbicide Active Ingredients Against Aquatic Weeds (EDIS Pub #SS-AGR-44)
Variable-leaf milfoil, Two-leaf water-milfoil – Myriophyllum heterophyllum
Variable-leaf milfoil is a native plant. As with most other Florida milfoils, this species is mostly submersed. However, it is also found with emersed leaves. In this sitation, 12 feet below the surface of the fast-flowing Ichetucknee river, variable-leaf milfoil grows luxuriantly, but only has the submersed leaf form. It is also found in shallow and slow-moving waters. Variable-leaf milfoil stems are reddish, somewhat stout, and may be several feet long. As its name implies, variable-leaf milfoil has more than one leaf form: a submersed form and an emersed form. The submersed leaves are limp, deeply divided, and feathery. They are about 2 inches long and an inch wide. The bright-green emersed leaves are held above the water on stems that are about 4 inches long. The emersed leaves are very small: only ½ to ¾ inch long, and 1/16 inch wide. They are linear shaped and relatively stiff. Both submersed and emersed leaves are arranged in whorls of 4 to 6 about the stem. The flowers of variable-leaf milfoil are reddish and very tiny: only about a millimeter or so across. They have four petals and grow in whorls of 4 to 6.
- The native variable-leaf milfoil is a submersed plant with long stems.
- It has two leaf forms: submersed leaves are feathery; emersed leaves are very small, linear, and stiff.
- The flowers are reddish and very tiny.