FLORA AND VEGETATION OF CONEFLOWER GLACIAL DRIFT HILL PRAIRIE NATURAL AREA, MOULTRIE COUNTY, ILLINOIS

摘要

The vascular flora of Coneflower Glacial Drift Hill Prairie Natural Area in Moultrie County, east-central Illinois, was studied during the growing seasons of 2002 and 2003. The prairie is located on a steep SW-facing hillside of the Cerro Gordo Glacial Moraine, overlooking the Kaskaskia River Valley and Lake Shelbyville. The flora was documented by general reconnaissance, and the structure of the vegetation was sampled in September 2003 using 0.25 m2 plots placed along two transects. The site supported 164 vascular plant species (including one named hybrid). The native grasses with the highest importance values were Andropogon gerardii (big bluestem) and Schizachyrium scoparium (little bluestem). Important forbs included Euphorbia corollata (flowering spurge), Helianthus divaricatus (woodland sunflower), Ratibida pinnata (drooping coneflower), and Comandra umbellata (false toadflax). Exotic species were represented by 28 taxa, 16.4% of the flora. The community had a Floristic Quality Index of 38.82, indicating a site of statewide significance.