Definition
Myriophyllum, also known as watermilfoil, is a genus of aquatic plants with feathery leaves, often found submerged in freshwater habitats. Think of it as the underwater fern of lakes and ponds. Unlike showy water lilies, myriophyllum provides critical habitat for aquatic life. Some species can become invasive, outcompeting native plants. They are used in aquariums for oxygenation and decoration, if the water is not too warm.