Flat sedge is an emersed plant. Its overall appearance is typical of this large genus. Flat sedge grows abundantly along every kind of marshy shore and wet clearing. Parts of rusty flat sedge are eaten by ducks and other birds. There are over 50 species and varieties of Cyperus in Florida (Wunderlin, 2003). Flat sedge occurs in the eastern half of the U.S. and the along the Pacific coast; in PR and the Virgin Islands; and in eastern Canada (Kartesz, 1999).
Cyperus odoratus grows from 4 to 30 inches tall. It may have only a few leaves rising from the base, and a few loose sheaths. Leaves are about 1/2 inch wide and may be as long as the plant. The base of the inflorescence has 3 to 10 conspicuous leaf-like bracts. The bracts are about 1/2 inch wide and can be much longer than the inflorescence. The inflorescence may be from 1 to 18 inches long. It has several small bottlebrush-like clusters of spikelets.
For brief control information, see Efficacy of Herbicide Active Ingredients Against Aquatic Weeds by K. Langeland, M. Netherland, and W. Haller.