cordgrass is usually relatively narrow with a we 11 -developed upper 

 zone of saltmeadow cordgrass mixed with saltgrass. Saltmeadow cord- 

 grass often occupies a larger area than smooth cordgrass. Pure stands 

 of black-grass in the higher parts of the zone often form a fringe at 

 the edges of the uplands. 



Marshes in the mid-Atlantic region undergo subtle changes from the 

 New England type on Long Island to the South Atlantic type at the 

 Virginia Capes. There are relatively limited areas of smooth cord- 

 grass with the greatest area covered by saltmeadow cordgrass. Local- 

 ized high salinity patches are dominated by pickleweed (Salioomia 

 spp.) Big cordgrass (Spart-ina aynosiccoides) and several rushes {Soivpus 

 eppO occur along creeks and tidal stream mouths where the freshwater 

 influence is greater. Black needle rush increases in importance near 

 the mouth of the Chesapeake Bay. The tall form of smooth cordgrass 

 appears along creek banks . 



South of the Chesapeake Bay, the South Atlantic and gulf coast 

 marshes typically form behind barrier beaches and in estuaries where 

 rivers deposit heavy silt burdens. Smooth cordgrass occupies vast 

 areas of mostly soft sediments between mean sea level (MSL) and mean 

 high water (MHW) . Large areas of high marsh, primarily black needle 

 rush, occur where astronomical tides are restricted and wind setup pre- 

 dominates; e.g., in Pamlico Sound, North Carolina. South of Daytona 

 Beach, Florida, the typical South Atlantic marshes are largely replaced 

 by mangrove trees that form the tropical and subtropical equivalent of 

 salt marshes. Marshes of the South Atlantic type occur on the northeast, 

 north, and west gulf coasts with the largest expanses on the Mississippi 

 River delta. Smooth cordgrass occupies the areas regularly flooded by 

 saltwater with brackish marsh of saltmeadow cordgrass, saltgrass, and 

 black needle rush covering vast areas. Gulf cordgrass {Spartina spar- 

 tinae) replaces saltmeadow cordgrass above MHW on fine-textured soils 

 along the coasts of Texas and southwestern Louisiana. Hyper saline 

 conditions in the Laguna Madre, due to limited rainfall and high tem- 

 peratures, largely exclude coastal marshes from the south Texas coast. 

 Black mangroves {kvioennia germinans) occasionally appear southward of 

 Galveston and on offshore islands farther north. 



b. West Coast . Vegetation on the west coast marshes is less uni- 

 form than on the east coast. Pacific cordgrass {Spartina folio so) , the 

 west coast equivalent of smooth cordgrass, occurs only along the central 

 and southern California coasts. Pickleweeds, which are widely distrib- 

 uted but of little importance on the east coast, are major plants along 

 the west coast. Sedges {Carex spp.), arrowgrass (^Triglochlin maritima) , 

 and tufted hair grass {Desahampsia caespitosa) become important north- 

 ward of the range of Pacific cordgrass. Saltgrass occurs all along the 

 west coast, but as on the east coast, it is seldom dominant over much 

 area (Cooper, 1969; Jefferson, 1973). 



