Spartina alrerniflora, or cordgrass, is the dominant native species in salt marshes along the Atlantic coast and the Gulf Coast of the United States. A. Spartina is very well adapted to conditions in salt marshes, where it plays a valuable role in stabilizing them and making them highly productive marine habitats. B. Spartina expands by growing root systems that float on the water's surface and descend underground, where it finds the nutrients that it needs to germinate. C. As a result of its spread in Washington State over the past hundred years,Spartina has now become a threat to native oysters by releasing sediments that contain sulfides into the waters. D. The dead leaves of Spartina become food for a wide variety of marine organisms. E. Outside its native regions, Spartina can pose serious problems by turning mudflats into high marshes that are inhospitable to many native fish and birds. F. Spartina has physiological adaptations that allow it to grow in environments where other plants cannot, making it a very strong competitor that is difficult to control once it is established.