This study of the vascular plant taxa in this region includes keys, descriptions, habitats, distributional data, and pertinent synonymy to every vascular species without cultivation in the southeastern United States. The Asteraceae is the largest family of flowering plants in the temperate zone and numbers over fifteen thousand species. Although one of the easiest families to recognize, many genera have been poorly defined heretofore. Geographical Range Vascular Flora of the Southeastern United States covers the forested region of the southeastern United States west to the prairie and north to the southernmost terminal moraines. This region includes Delaware, Maryland, Virginia, North Carolina, South Carolina, Georgia, Florida, Alabama, Mississippi, Louisiana, Arkansas, Tennessee, Kentucky, and West Virginia. Notation of presence in adjacent states of Texas, Oklahoma, Missouri, Illinois, Indiana, Ohio, Pennsylvania, and New Jersey will be made.