The plants that live in rivers provide an important role in the river's overall ecosystem. They provide food and shelter for the river otters, muskrats, snakes, turtles and other animals that make rivers their home. River plants contribute to high oxygen levels and cleaner water, according to the University of California, Museum of Paleontology. A wide variety of aquatic plants are found in the water and growing along the riverbanks.

Rivers contain an abundance of aquatic plants.

Fragrant Water Lily

A blooming flower on a water lily.

The fragrant water lily is one of the most common aquatic plants, according to the Department of Ecology. The large, round leaves float on the top of the water, and have a distinctive slit on one side. The plant bears fragrant flowers that are pink, white, or purple with a yellow center. The flowers are approximately 2 to 4 inches across and bloom from June through October. The leaves and roots of the fragrant water lily are eaten by beavers, deer, porcupines and muskrats.

Water Primrose

Blooms of the water primrose.

Water primrose is a robust plant that has willow-like leaves and bright yellow flowers. It forms dense mats, and is very common in the southern United States. Yellow flowers bloom throughout the summer on stalks that originate from leaf bases. The flowers have five petals and five sepals. The plant provides food for waterfowl and muskrats. This perennial herb can be found growing upright, floating on the water surface or creeping on the shoreline.

Yellow Floating Heart

Two flower blooms on yellow floating heart.

The yellow floating-heart is a water lily-like plant; however, it is not in the water lily family. It carpets the water's surface with heart-shaped leaves. This plant is a native of Europe, and can be found growing in Mediterranean areas and North America. The rope-like stem will grow along the sediment surface or partly underground. Yellow floating heart has heart-shaped leaves approximately 4 inches in size, and floats on the water's surface. Two to five bright yellow flowers will bloom on erect flower stalks. Each flower has five petals that are arranged like the spokes of a bicycle wheel and each petal has a distinctive fringe along the edges.

Flowering Rush

Flowering rush floating in a river.

Flowering rush is an aquatic perennial that is found in a variety of shallow, fresh-water habitats like slow-moving rivers and on the shoreline of lakes. The plant produces a round-topped flower cluster that consists of 20 to 50 light pink flowers. Each flower has three pink sepals and three slightly larger pink petals. The leaves are thin, long and straight, and grow to approximately 40 inches long. Flowering rush is a non-native, invasive plant that can be found in Canada and northeastern United States, as stated by the Department of Ecology.