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Hydrilla verticillata (L. f.) Royle
Synonym: Waterthyme
Hydrilla Hydrilla
Brian Nelson, SW Florida Water Mgt. Dist.


Commodities Affected:



Hydrilla adversely affects aquatic ecosystems by forming dense canopies that often shade out native vegetation. Extensive mono-specific stands of hydrilla can provide poor habitat for fish and other wildlife.  It was sold as an aquarium plant, which may have been the origin of its initial introduction into natural water systems. However, it is now listed by the federal government, and most states, as a noxious weed. As a result, its sale in recent years has been limited.



On August 31, 2006, hydrilla was confirmed in Lake Manitou (Fulton County, at Rochester). This is the first report of this species in Indiana.