Results from quantitative research on the community composition of dry prairies across Iowa were consolidated from three different studies completed since 1983. Information is provided on the distribution and abundance of 204 dry prairie species. The most abundant species included little bluestem (Schizachyrium scoparium (Michx.) Nash), big bluestem (Andropogon gerardii Vitman), side-oats grama (Bouteloua curtipendula (Michx.) Torrey), prairie dropseed (Sporobolus heterolepis (Gray) Gray) and Kentucky bluegrass (Poa pratensis L.). Multivariate analyses were completed using two independent measures of species abundance-relative cover and community constancy. When relative cover was used to determine community composition, the abundance of graminoids (tallgrasses vs. mid-grasses) had a strong effect on community composition and variation was mostly influenced by soil moisture. When community constancy was used to determine community composition, forbs had a higher representation and plant biogeography had a strong effect on variation in community composition