South Florida’s Everglades, which are the focus of an $8 billion, 30-year restoration plan, have diverse subtropical wetland plant communities. In May and October, 1999, we censused 240 sites in the Everglades for plant species presence and relative abundance, then used UPGMA to cluster these sites into groups based on this data. Sites were chosen in a stratified-random sampling design, and 1 or 2 10-m transects were sampled at each site for a total of 418 transects. Soil and water nutrients were also analyzed for each site. The species present were determined for 5 1-m2 quadrats per transect. Each quadrat was subdivided into 4 0.25-m2 units. We found 161 taxa, but 91% of these occurred in fewer than 10% of the transects. Transects had a mean of 5 species (range = 0 – 30). When the transects were aggregated into 8 clusters, we had 4 small clusters with 1-3 transects each and 4 larger clusters. The larger clusters were a sawgrass (Cladium jamaicense) cluster, a spikerush (Eleocharis cellulosa) cluster, a water lily (Nymphaea odorata) – bladderwort (Utricularia purpurea) cluster, and a cattail (Typha domingensis) cluster. Some commonly recognized Everglades plant associations, such as maidencane (Panicum hemitomon) and beakrush (Rhynchospora tracyi) flats, did not form distinct clusters in our analysis. The absence of large clusters defined by these species could represent differences among studies in scale or type of analysis, or it could reflect historical changes in the Everglades ecosystem. Logistic regression of species occurrence against soil phosphorus (P) or ash-free dry weight (AFDW) showed that sawgrass occurs across a broad range of P levels and soil types, while cattails increase in abundance with increasing soil P. Beakrush, bladderwort and spikerush are found at relatively low soil P, and water lilies are found in soils with intermediate P and high AFDW.

Key words: Cladium, Eleocharis, Everglades wetland plant communities, Nymphaea, Typha, Utricularia