River plants serve an important ecological function. Many of them provide shade and food for birds, fish and other wildlife. They also help to oxygenate the water and can stabilize the sediments in the water to keep the water clear. These plants prefer the moisture and can tolerate shade. River plants have adapted to living on or in the water.
Fragrant White Water Lily
The fragrant white water lily (Nymphaea odorata) is a perennial river plant that has heart-shaped leaves that grow up to 12 inches in diameter. The flowers are white with yellow centers that float or stick above the water's surface. They open in the daytime and close at night and are extremely fragrant. This plant's roots are an important food source for fish and the seeds are often eaten by ducks.
European Frogbit (Hydrocharis morsus-ranae) is a small, aquatic, perennial plant that resembles the water lily. The heart-shaped leaves are 1 to 2 inches in diameter. The plant is considered invasive because it can spread quickly. Frogbit will form a thick, dense mat on the water's surface, which can prevent oxygenation. It is a free-floating plant with a small, white flower.
Water moss (Fontinalis antipyretica ) is a submerged, evergreen plant. It attaches itself to rocks, logs and other objects in flowing water by rhizoids, or rootlets. The leaves are only a few millimeters long and are small, rigid and pointed. They grow together to form a carpet-like area, which is occasionally a home to small fish. Water moss does not produce flowers, instead it has spores that help with reproduction. It prefers shady areas in water that is slightly acidic.
The water horsetail (Equisetum fluviatile) grows in dense colonies in shallow water and moving water. The stems are tall, slender, hollow and can reach up to 3 feet tall. This plant does not flower; it has a spore-producing tip at the end of the stems. Water horsetail is usually found in deeper waters than regular horsetail because the stems are more fragile and can easily be crushed by the faster-moving water along the shore. It prefers full sun but is tolerant of shade. According to the State of Washington's Department of Ecology, the stems were once used by Europeans and native Americans as a scouring and sanding device because of the high silica content.