Hydrilla was originally introduced in the United States as an aquarium plant. Hydrilla has spread throughout the US and abroad. It grows rapidly from fragments, tubers and turions, and can remain dormant for 7+ years. Hydrilla is unintentionally and easily spread from small weed fragments severed by boat motors. It is transported from lake to lake attached to boat trailers or motor propellers. Since it can grow as much as eight inches a day in clear water, this noxious plant can establish itself quickly and spread rapidly.