Sea oats are the most important and widespread grass on southern coastal dunes. They get their name from the large plumes that are produced during summer. Sea oats are a species of perennial grass that can grow to a height of 3-6 feet and are commonly associated with the upper dunes along beach fronts. Sea oats once blanketed the coastal landscape along the southeastern US from North Carolina to Florida, and found their way to the panhandle. However, they are now endangered in Florida.

Although the sea oats look like a weed, they are much more. They have narrow leaves that can grow to 24 inches and are often brown and curled in appearance. During the summer, sea oats have a loose branching cluster of flowers called a panicle which are made up of many flat small spikes containing seed. The panicle turns from green to straw in late summer as the plant matures. Sea oats are considered hardy plants that are drought resistant and are immune to some fungus infections that can plague other grasses.

Sea oats have a massive root system. If a sea oat is buried by sand, it develops vertical rhizomes (underground stems) which grow to produce an offspring plant. The root system can have rhizomes and roots that can reach up to 30 feet below the top of the dune. Although sea oats respond well to fertilization, they require little or no nutrient input when grown in the wild. In addition, there are no known pests or problems that plague these plants.

The plants tolerate salt spray and temporary floodings with salt water. However, they will not tolerate being water-logged. The network of roots underground allow sea oat leaves and stems to trap wind-blown sand, thus increasing the size of the dunes. Dunes function as dikes against flooding from large ocean waves and as reservoirs of sand to seasonally replenish the beach. During hurricanes, sand dunes help reduce the energy of storm waves.

Florida sea oats are protected under regulations of the Florida Department of Environmental Protection (FDEP). This is because the sea oats vegetation is essential to the coast's ecosystem. Sea oats seeds cannot be collected without a permit and the plants cannot be cut back or removed. However, they are easy to grow without breaking the law, since you can buy sea oats seeds legally from certain nurseries.