Vegetation present in three abandoned rice fields of the Winyah Bay Estuary at the Belle W. Baruch Institute for Marine Biology and Coastal Research, Georgetown County, South Carolina, observed in 1968 was compared with the vegetation present in 1987-91. Species composition in the three marshes changed little in 20 years. The index of similarity is high (greater than 0.80) for each site. There has been a decline in the total number of species present in the Airport and Alderly Marshes. Ninety-four percent of the species observed in 1968 and 1991 are indigenous to the United States. Phragmites australis, an aggressive rhizomatous perennial, is rapidly colonizing the Airport and Alderly Marshes.