The sea oat is probably the most iconic of all beach dune plants and a vital one at that. It is considered a primary beach stabilizer because of its massive root system. Sea oats are also important both as a source of food and habitat for birds, small mammals and insects. Sea oats bloom spring through summer, producing a large head full of flowered spikelets.
Source: Wild South Florida
http://www.wildsouthflorida.com/sea.oats.html#.WaClV4qQxE4