An analysis of floating vegetation mat communities in Grassy Lake, a southwestern Arkansas bald cypress swamp, is presented. <em>Decodon verticillatus</em> (waterwillow) is the dominant species, and <em>Zizaniopsis miliacea</em> and <em>Hydrocotyle verticillata</em> are important secondary species. The successional pattern includes a pioneer stage dominated by <em>D. verticillatus</em>, a water-willow-herbaceous stage, a water-willow-herb-shrub stage, and finally a tree stage dominated by bald cypress. The successional pattern differs from the sequence of stages reported from other areas of the Southeastern United States. It is suggested that floating vegetation mats provide a mechanism for bald cypress seedling establishment in a relatively permanent flooded pool.