Native to: South America
Alligatorweed was accidentally introduced into Florida in 1894 in ships' ballast water and can now be found growing throughout the state. This rooted perennial plant can grow in various habitats, although it is usually found in water. It forms sprawling mats over deep rivers or along shorelines and can be a pest on land.
Thick mats of alligatorweed prevent drainage canals, ditches, streams, and other small waterways from emptying rapidly during periods of heavy water load, thus causing flooding. If mats break loose, they create obstructions by piling up against bridges, dams, and sharp bends in waterways. Thick mats also increase mosquito habitat. Navigation of small waterways is obstructed, as is shoreline navigation in large waterways. Fishing and swimming can be affected, although a small fringe of alligatorweed probably benefits fishing.
Alligatorweed should be removed and disposed of properly to prevent spread.
Because alligatorweed spreads easily by fragmentation, attempts at physical control usually only serve to spread the weed.
Because alligatorweed spreads easily by fragmentation, attempts at mechanical control usually only serve to spread the weed.
Three insect species have been introduced into the United States as biological controls:
The active ingredients that have been successful in treating alligatorweed include: