From North America to anywhere else

Ceratophyllum demersum is a native of North America. It now has a worldwide distribution, at least in part due to the aquarium and pond trade. It is a submerged aquatic plant which is capable of forming dense monospecific beds, excluding other plant species, causing problems to recreational activities on waterways and in some cases causing blockages at hydroelectric power stations. C. demersum can spread rapidly, and grows in a large range of aquatic habitats.