A plant that grows in a pond; crayfish eat elodea

Elodea is a genus of aquatic plants often called the Water weeds. Elodea is native to North America and it is also widely used as aquarium vegetation. 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.

submerged freshwater perennials