Hydrilla (Hydrilla verticillata) is native to parts of Asia, Africa, Australia and Europe. Hydrilla was introduced to the United States in the 1950’s as an aquarium plant. Hydrilla is referred to as “The Perfect Weed”: because it tolerates a wide range of water conditions, easily reproduces, spreads by multiple methods, and is difficult to control. Hydrilla can grow in water depths of a few inches up to 35ft.