Myriophyllum (water milfoil) is a genus of about 45 species of freshwater aquatic plants, with a cosmopolitan distribution. Its name comes from Latin, "myrio" meaning "too many to count", and "phyllum", meaning "leaf".

These submersed aquatic plants have whorled leaves that are finely, pinnately divided. The leaves above the water are stiffer and smaller than the submerged leaves on the same plant. The flowers are small with four petals and are borne in the leaf axils or in a terminal, emergent spike.

Waterfowl eat the fruits and leaves and muskrats eat the entire plant.

It has a long soft but fairly brittle stem. The leaves of the plant only present near surface of the water, while flowers are formed above the surface of the pond.

Various species of water milfoil have become naturalized in water bodies of nearly every state in the continental U.S.

This plant may be a hidden resource, eventually seen as a valuable cellulose feed stock in a biofuel refinery.Cellulosic ethanol, or butanol fuel are seen by many as growing trends in green fuels (including jet fuel).

Control

A common species, Eurasian water milfoil, is often controlled with herbicide containing the chemical diquat dibromide. Control can also be done through careful mechanical management but caution must be used since this is a fragmenting plant, and the fragments may grow back. Milfoil is an invasive aquatic plant species from Asia.

Mechanical management can include the use of a long reach lake rake or aquatic weed razor blade tool. Using these tools would be similar to lawn work. These tools are most effective before seeds set. Another very effective use is to keep the plants from ever starting to grow through the use of a Weed Roller or a Beach Groomer. These are considered to be automated and unattended machines. Permits may be required by various states. A guide to state permits and aquatic vegetation management can be found at http://www.WeedersDigest.com

Recently, Professor Sallie Sheldon of Middlebury College has found that an aquatic weevil (Euhrychiopsis lecontei), which eats nothing but milfoil, may be the most effective weapon against it. [90389]

Selected species

• Myriophyllum alterniflorum
• Myriophyllum aquaticum
• Myriophyllum diccocum
• Myriophyllum elatinoides
• Myriophyllum farwellii
• Myriophyllum heterophyllum
• Myriophyllum hippuroides
• Myriophyllum humile
• Myriophyllum laxum
• Myriophyllum matogrossense
• Myriophyllum pinnatum
• Myriophyllum quitense
• Myriophyllum sibiricum
• Myriophyllum spicatum
• Myriophyllum tenellum
• Myriophyllum tuberculatum
• Myriophyllum ussuriense
• Myriophyllum variifolium
• Myriophyllum verrucosum
• Myriophyllum verticillatum

See also

• Cellulosic ethanol