Brazilian Elodea (egeria densa) was introduced to this country about 100 years ago. It was an attractive oxygen producing plant primarily sold as an aquarium plant. It can now be found in 40 States including Hawaii.
It is an aggressive lake weed, very similar to both American Elodea and Hydrilla. All three are submersed and rooted to the lake bottom. Leaves of Brazilian Elodea have minute teeth not visible by the naked eye. It spreads primarily by floating fragments that simply re-root. It does not use seeds or tubers. Stems are long and slender and rarely branch. Each leaf is 2 cm long and whorls the main stem in groups of 4. Three peddled flowers are white and slightly smaller than a dime. Only branches that sprout from double nodes form new plants when fragmented. American Elodea is smaller, 3-1 cm leaves whorl around stem. Hydrilla has 5 serrated leaves whorling around stem with reddish midribs produce tubers. Brazilian and American Elodea do not have tubers.
Brazilian Elodea is an exotic, aggressive lake weed with few predators. It can take over your pond or small lake and eliminate native lake weeds. Dense mats cease to produce oxygen during hot nights and reduce fish mobility which can cause fish kill. These dense mats also reduce the ability to maintain proper fish population and balance. Brazilian Elodea interferes with swimming, boating, fishing and water skiing. It clogs water intakes, traps sediments and crowds out native vegetation.
Two good ways for Brazilian Elodea lake weed removal are:
Herbicides are the most effective method of control. Fluridone (Sonar Q Granular & Restore Liquid), diquat (Weedtrine-D Liquid), and endothall (Hydrothol Granular).
Grass Carp appear to find Brazilian Elodea very palatable. Texas Department of Parks & Recreation recommends 7 Grass Carp per acre. Contact your local environmental agency for dealers in your area and to determine proper stocking rate for your pond.
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