Sporobolus pumilus, the saltmeadow cordgrass, also known as salt hay, is a species of cordgrass native to the Atlantic coast of the Americas, from Newfoundland south along the eastern United States to the Caribbean and north-eastern Mexico. It was reclassified after a taxonomic revision in 2014, but the older name, Spartina patens, may still be found in use. It can be found in marshlands in other areas of the world as an introduced species and often a harmful noxious weed or invasive species.

It is a perennial grass found in the upper areas of brackish coastal salt marshes. It is a slender and wiry plant that grows in thick mats 12 to 24 inches (30 to 60 cm) high, green in spring and summer, and turns light brown in late fall and winter. The stems are wispy and hollow, and the leaves roll inward and appear round. Because its stems are weak, the wind and water action can bend the grass, creating the appearance of a field of tufts and cowlicks. Like its relative smooth cordgrass, saltmeadow cordgrass produces flowers and seeds on only one side of the stalk. Flowers are a deep purple from June to October and turn brown in the winter months.

Saltmeadow cordgrass is found in high marsh zones where it is covered at times by high tides. Specialized cells are able to exclude salt from entering the roots, preventing the loss of fresh water. This grass is, however, less tolerant of saltwater than some other marsh grasses. It can also grow on beaches and can quickly recolonize an overwash zone.

A healthy salt marsh depends on the presence of plants such as salt hay grass and smooth cordgrass. These grasses provide rich habitat for crustaceans, mollusks, and birds, and serve as a major source of organic nutrients for the entire estuary. Mats of salt hay grass are inhabited by many small animals and are an important food source for ducks and seaside sparrows.