Prior to European settlement, the portion of north and central Florida corresponding to the historic range of longleaf pine (Pinus palustris) was dominated by fire-dependent, herbaceous and open woodland plant communities. Economic development coupled with fire suppression lead to a drastic decline in the abundance, contiguity and integrity of these natural communities. We present a classification and description of natural, fire-maintained pineland communities of this highly fragmented landscape. Plot locations were stratified by region and topographic position to assure comprehensive coverage of compositional variation associated with local and regional gradients of environmental and geographic variation. Our focus was description of groundcover vegetation, which harbors most of the plant diversity. We censused all plant species within 293 vegetation plots of 1,000 m². We then developed a comprehensive vegetation classification based on floristic similarity using K-means cluster analysis and ordination. Sixteen distinct “communities” are recognized, corresponding to plant assemblages that we deem readily discernable in the field. These communities were grouped into five ecological “series” corresponding to those of Peet: Xeric Sandy Uplands (2 communities), Subxeric Sandy Uplands (2 communities), Silty Uplands (2 communities); Flatwoods (3 communities); and Wetlands (7 communities). For each community we summarize species diversity, woody plant structure, diagnostic (indicator) species, and environmental and physiographic characteristics. Floristic variation within and between series is described relative to geographic variation and edaphic characteristics.