In geography , a marsh is a type of wetland , featuring grasses , rushes , reeds , typhas , sedges , and other herbaceous plants ( possibly with low-growing woody plants ) in a context of shallow water . In geography , a marsh , or morass , is a type of wetland that is subject to frequent or continuous flood . Typically the water is shallow and features grasses , rushes , reeds , typhas , sedges , other herbaceous plants , and moss .