Freshwater plants are found in rivers, streams and ponds throughout the U.S. They perform several important functions including erosion control, oxygenation and purification of the water, as well as providing food and shelter for wildlife and sometimes, for humans. Thousands of freshwater plants grow in waterways, but only a few are very common.
Fragrant Water Lily (Nymphaea odorata) grows in still water that is up to 8 feet deep. It forms roots in mucky soil, then sends out long petioles to the surface of the water where the leaves and flowers are formed. It is different from most plants because the tiny holes in the leaves where air is exchanged with the atmosphere are located on the top of the leaves rather than the bottom. The leaves can be as much as 4-12 inches across and the flowers are considered very fragrant.
Cattail (Typha latifolia) is an important freshwater aquatic plant that is native to the U.S. The roots and new shoots are eaten by wildlife, and the fluffy seeds on mature seed heads are used by birds to make nests. The plants themselves are used as shelter by birds and other aquatic creatures. Also, the strong roots prevent erosion and help clarify water as it runs into the waterways. Cattail is a grassy plant and the seed heads are long and cinnamon-colored.
Skunk Cabbage (Symplocarpus foetidus) is found along stream beds where water levels fluctuate often. The distinct purple flower heads appear in early spring and the leaves emit an unpleasant smell when crushed. The flower of the plant has the unusual ability to produce heat, which attracts flies that are the plant's most important pollinator. The leaves appear a few weeks after the bloom.
European or Eurasian milfoil (M. spicatum) is best known as a plant used by aquarium enthusiasts. It floats on the surface of the water creating dense mats that can interfere with the oxygenation process created by moving water. Although present in U.S. waterways since the 1800s and considered an exotic or invasive species, milfoil is a common and widespread freshwater plant. It is spread from one waterway to another by boaters and aquatic birds. New plants can grow from only one tiny segment of another milfoil plant.