Spartina is a genus of plants in the grass family, frequently found in coastal salt marshes. Species in this genus are commonly known as cordgrass or cord-grass, and are native to the coasts of the Atlantic Ocean in western and southern Europe, north-western and southern Africa, the Americas and the islands of the southern Atlantic Ocean; one or two species also occur on the western coast of North America and in freshwater habitats inland in the Americas. The highest species diversity is on the east coasts of North and South America, particularly Florida. They form large, often dense colonies, particularly on coastal salt marshes, and grow quickly. The species vary in size from 0.3–2 m tall. Many of the species will produce hybrids if they come into contact.

A salt marsh, saltmarsh or salting, also known as a coastal salt marsh or a tidal marsh, is a coastal ecosystem in the upper coastal intertidal zone between land and open saltwater or brackish water that is regularly flooded by the tides. It is dominated by dense stands of salt-tolerant plants such as herbs, grasses, or low shrubs. These plants are terrestrial in origin and are essential to the stability of the salt marsh in trapping and binding sediments. Salt marshes play a large role in the aquatic food web and the delivery of nutrients to coastal waters. They also support terrestrial animals and provide coastal protection.