The floristic composition of Beadles Barrens Nature Preserve, located in west-central Edwards County, Illinois was studied during the growing seasons of 1999–2002. The vascular flora of this 4.0 ha preserve consisted of 306 species in 75 families, including 65 species not previously reported from Edwards County. The herbaceous layer was dominated by prairie grasses with Schizachyrium scoparium (Michx.) Nash (IV = 61.5 of 100) being the most abundant. Many other prairie species were common with Soliadgo nemoralis Ait., Pycnanthemum tenuifolium Schrad. and Carex spp. having the highest importance values. Trees were sparse with most occurring in a small (0.125 ha) grove located in the northwest corner of the barrens. Tree density in the grove was 432 trees/ha with Diospyros virginiana L. (IV = 54.6) and Quercus stellata Wangh. (IV = 53.9) being co-dominants. Herbaceous species were also sparse in the grove, consisting of Danthonia spicata (L.) Roem. & Schultes, Antennaria spp., and Lechea tenuifolia Michx. The Floristic Quality Index for the site was 61.3.