Animals and plants live in these zones of the marsh, depending on how well they can withstand the drier conditions of the upper marsh or the wet conditions that regularly occur in the lower marsh. Smooth cordgrass is the most abundant salt marsh plant in South Carolina and is responsible for much of the marsh's productivity. Spartina 's successful adaptations enable it to live where few other plants could survive. It has narrow, tough blades and special glands that secrete excess salt, making it ideal to withstand the high heat and daily exposure to salt water. Few animals eat this plant, but many animals and plants live on it or on the marsh surface protected by its roots and stalks.
Spartina stalks are thick and are very tough and well anchored by a root system.
A tall form grows along creek banks and can reach heights of 9 feet. A short form of Spartina occurs in interior parts of the low marsh and ranges from 2 to 3 feet in height. In contrast to the low marsh which has one major species of plant, the high marsh contains a mixture of several species including black needlerush, salt meadow cordgrass and short-form smooth cordgrass. This high marsh area grades into a marsh-upland border which is a transitional zone between the salt marsh and the maritime shrub community that consists of wax myrtle, yaupon and cedar. South Carolina also has brackish marshes which occur in water of lower salt content.