Full grown and flowering they are about 18"-2' tall. I've thumbed through Peterson, Edible wild plants; Peterson, Medicinal plants; Audubon, Eastern Edition wild flowers and Wildflowers of Tenn, Ohio Valley and Southern Appalachians. To this point I've found nothing that looks similar.
http://i862.photobucket.com/albums/a...ronc/Plant.jpg
http://i862.photobucket.com/albums/a...onc/Plant1.jpg
http://i862.photobucket.com/albums/a...onc/plant2.jpg