This is a highly invasive aquatic species of estuaries and wetlands that arose in England from a fertile hybrid of the European small cordgrass (Spartina maritima) and the (probably) accidentally introduced American smooth cordgrass (Spartina alterniflora) (Nehring and Hesse 2008). This is a deep rooting perennial species that spreads by rhizomes to form extensive meadows and swards. It was widely used for for coastal protection (stabilization and land reclamation) along ocean shorelines in various countries, including Africa (Global Invasive Species Database 2010) but colonized large areas of tidal mudflats and saltmarsh, altering these ecosystems and affecting native populations of flora and fauna. It spreads through seed dispersal on ocean currents, by birds, and by accidental spread through ship ballast water.

Spartina anglica is now found in North America in British Columbia, Washington and California (USDA 2010). It was introduced in Puget Sound, Washington, in 1961 (Williams 2004), and was discovered in British Columbia in 2003 by Gary Williams on Robert's Bank in the Fraser River estuary. "Spartina anglica is [now] the dominant Spartina species in Boundary Bay." (Lomer pers. comm. 2013).