Sedges include many wild marsh and grassland plants, and some cultivated ones such as water chestnut ("Eleocharis dulcis") and papyrus sedge ("Cyperus papyrus"). These species are widely distributed, with many in tropical Asia and tropical South America. Sedges may be found growing in almost all environments. Many are wetlands, or have poor soils. Ecological communities dominated by sedges are known as sedgelands.