Marshes, one of the most easily recognized freshwater wetlands, are commonly found along lake and pond shores, and river edges. The depth and duration of surface water in a marsh varies; some marshes may be flooded seasonally, while others may have permanent surface water. Common marsh plants include sedges (Carex sp.), cattails (Typha sp.), rushes (Juncus sp.), and flowering herbs such as pickerelweed (Pontederia cordata) and arrowhead (Sagittaria sp.)
Marshes provide valuable habitat for wildlife that use marshes for breeding, nursery grounds, feeding, and resting sites. Marshes can also improve water quality by filtering excess nutrients, sediment, and pollutants out of the surface water.