A taxonomic study of the vascular flora of Paynes Prairie State Preserve was conducted on the 1160 hectare southern upland property adjacent to the southern rim of the prairie basin. Plant communities of this area, forming a dynamic continuum and a changing vegetational mosaic, are typical of northcentral Florida and possess a moderately high degree of biological diversity. Collections of 573 species representing 123 families were made from January 1986 to December 1989 and are compiled in an annotated list. Voucher specimens have been placed in the University of Florida Vascular Plant Herbarium (FLAS). The species list and specimens will provide useful information for park personnel and other persons who are interested in the vascular flora and plant communities of northcentral Florida.