An aquarium tank containing sprigs of pondweed (Elodea sp.), an aquatic plant also known as Anacharis. Oxygen bubbles on the side of the tank are the result of photosynthesis. Elodea is a genus of closely related aquatic plants native to North America. They are important producers in pond ecosystems, and are used widely in home aquariums and school experiments. Some species have been introduced to Europe, Africa, Australia and other areas where they are considered a noxious, invasive species.