Sporobolus alterniflorus, or synonymously known as Spartina alterniflora, the smooth cordgrass, saltmarsh cordgrass, or salt-water cordgrass, is a perennial deciduous grass which is found in intertidal wetlands, especially estuarine salt marshes. It has been reclassified as Sporobolus alterniflorus after a taxonomic revision in 2014, but it is still common to see Spartina alterniflora and in 2019 an interdisciplinary team of experts coauthored a report published in the journal Ecology supporting Spartina as a genus. It grows 1–1.5 m (3.3–4.9 ft) tall and has smooth, hollow stems that bear leaves up to 20–60 cm (7.9–23.6 in; 0.66–1.97 ft) long and 1.5 cm (1⁄2 in) wide at their base, which are sharply tapered and bend down at their tips. Like its relative saltmeadow cordgrass S. patens, it produces flowers and seeds on only one side of the stalk. The flowers are a yellowish-green, turning brown by the winter. It has rhizoidal roots, which, when broken off, can result in vegetative asexual growth. The roots are an important food resource for snow geese. It can grow in low marsh (frequently inundated by the tide) as well as high marsh (less frequently inundated), but it is usually restricted to low marsh because it is outcompeted by salt meadow cordgrass in the high marsh.