Elodea

Classified in the frog's-bit family (Hydrocharitaceae), Elodea is native to the Americas[1] and is also widely used as aquarium vegetation and laboratory demonstrations of cellular activities.

[3] The introduction of some species of Elodea into waterways in parts of Europe, Australia, Africa, Asia, and New Zealand has created a significant problem and it is now considered a noxious weed in these areas.

The American water weed lives entirely underwater with the exception of small white flowers which bloom at the surface and are attached to the plant by delicate stalks.

This is the American water weed's most important method of spreading, while seed production plays a relatively minor role.

It is also of economic importance as an attractive and easy to keep aquarium plant, although in the states of Alabama, New Hampshire, New York, and South Carolina it has been deemed Elodea densa an invasive species and is illegal to sell.

Torn fragments can be transported downstream or are introduced to new environments via attachment to boats and anchor chains.

An aquatic weed harvester collecting Elodea from a lake