The species composition of grassland and ecotonal communities throughout the Loess Hills was studies between 1990 and 1993. Information pertaining to the latitudinal distribution of species in the Loess Hills, the abundance of species among community types (i.e., habitats), species persistence under woody encroachment, species associations, and resource partitioning among species is provided for the majority of grassland species occurring in the Loess Hills. The most abundant species on extant prairie in the Loess Hills include Bouteloua curtipendula (side-oats grama), Schizachyrium scoparium (little bluestem), Andropogon gerardii (big bluestem), Cornus drummondii (rough-leaved dogwood), Aster ericoides (heath aster), Carex heliophila (sun-loving sedge), Sisyrinchium camppestre (blue-eyed grass), Dichanthelium oligosanthes (Scribner\u27s panic grass), Amorpha canescem (lead plant), and Asclepias verticillata (whorled milkweed)