Marsh bristlegrass is a plant with a broad presence across the Americas, where it is native, and has been introduced to various regions in Asia, Europe, Africa, and Oceania. While cultivated periodically, marsh bristlegrass is sometimes thought to be competitive in certain areas outside its native range, particularly in parts of the Mediterranean, South America, and the Caribbean where it may have an impact on local ecosystems. However, the extent of its cultivation and potential influence on habitats varies globally.