"Hydrilla" (Hydrilla verticillata)

Hydrilla (Hydrilla verticillata) an Old World species that is thought to have been introduced to North America in Florida sometime during the 1950's, is an aggressive, invasive species and has spread throughout Florida and most southern states, as well as California, Delaware, and the District of Columbia. Hydrilla has been categorized as one of the world's worst weeds, and it is certainly among the most notorious of submerged aquatic plant species. Infestations of Hydrilla are extremely severe and can completely choke entire lakes and public water supplies. There are no effective control measures against Hydrilla once it has become established in a region.

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U.S. Geological Survey
Keyword: Hydrilla

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