Low-lying wetlands are areas of land that are covered in shallow water and are characterized by their unique vegetation. Swale, MORASS, MARSH, FEN, and MOOR are all terms used to describe different types of low-lying wetlands. A swale is a shallow depression in the land that is often filled with water. A MORASS is a marshy area of land that is often boggy and wet. A MARSH is an area of land that is permanently or seasonally flooded and is characterized by its grassy vegetation. A FEN is a type of wetland that is fed by groundwater and is characterized by its acidic soil. Finally, a MOOR is an area of land that is usually covered in heather and is often found in upland areas.