Freshwater marshes are common type of wetlands in southern Guam. Most are dominated by dense, nearly pure stands of Phragmites karka. Other grasses (e.g. Panicum muticum), sedges (e.g. Eleocharis ochrostachys and Cyperus spp.) and the fern Acrostichum aureum are also commonly present but are less prevalent. Freshwater marshes are important habitats for the endangered Marianas Common Moorhen (Gallinula chloropus guami) and migratory birds.