ETYM Old Eng. mersch, as. mersc, from mere lake. Related to Mere pool, and cf. Marish, Morass.
Low-lying wet land with grassy vegetation; usually is a transition zone between land and water; SYN. marshland, fen.
Low-lying wetland. Freshwater marshes are common wherever groundwater, surface springs, streams, or run-off cause frequent flooding or more or less permanent shallow water. A marsh is alkaline whereas a bog is acid. Marshes develop on inorganic silt or clay soils. Rushes are typical marsh plants. Large marshes dominated by papyrus, cattail, and reeds, with standing water throughout the year, are commonly called swamps. Near the sea, salt marshes may form.