Riparian areas or zones are the areas of vegetation directly separating land from water and immediately adjacent land that is frequently inundated, or, in other words, the floodways of streams.

Vegetation in riparian areas typically consists of plants that either are emergent aquatic plants, or herbs, trees and shrubs that thrive in close proximity to water. Typical riparian zone trees in the eastern United States include:

• Cottonwood, Populus deltoides
• Silver maple, Acer saccharinum
• Boxelder, Acer negundo
• American elm, Ulmus americana
• American sycamore, Platanus occidentalis
• Butternut, Juglans cinerea
• Black walnut, Juglans nigra
• Black willow , Salix nigra
• River birch, Betula nigra
• Green ash , Fraxinus pensylvanica
• Honey locust, Gleditsia triacanthos
• Basswood, Tilia americana

The assortment of riparian-zone trees varies from those of wetlands.

Other riparian zone plants include grasses, sedges, wingstem , and others.

Research has shown that riparian ecosystems are vital to the health of all other aquatic ecosystems as they filter out pollutants from land runoff, prevent erosion, and provide shelter and food for many aquatic animals.