Xeric limestone prairies occur in southwestern and southern Illinois. These small grassland communities are present on thin soil and commonly have relatively extensive areas of exposed rock. Warm-season clump grasses, primarily Schizachyrium scoparium and Bouteloua curtipendula, are dominant along with a mixture of prairie and open-forest species. The vascular flora of two xeric limestone prairies, located near the bluff line of the Mississippi River on the property of Mr. and Mrs. Ralph Buettner in Monroe County, Illinois, were surveyed in 2011. A total of 174 vascular plant species were recorded from the two prairies, with 60 species present in survey plots. Bouteloua curtipendula dominated the East prairie followed by Schizachyrium scoparium, Andropogon gerardii, and Ruellia humilis. Andropogon gerardii dominated the West prairie followed by Bouteloua curtipendula, Solidago ulmifolia, Aster oblongifolius, Tridens flavus, and Schizachyrium scoparium. Vegetation covers 38.0% and 33.5% of the surface in these two prairies, while exposed rock was between 17% and 19%, and bare ground and litter was from 40% to 44%.