Elodea canadensis (American waterweed or Canadian waterweed or pondweed) is a perennial aquatic plant, or submergent macrophyte, native to most of North America. It has been introduced widely to regions outside its native range and was first recorded from the British Isles in about 1836.
The native range of the species lies within North America, but it has been introduced in many parts of the world either intentionally or not. Europe has been particularly affected with the first record dating back ...