Silphium wasiotense Medley was recently described as S. wasiotensis (Medley 1989). Campbell et al. (1993) and Kartesz (1994) give “wasiotense” as the correct orthographic form of the epithet. Silphium wasiotense was previously known only from the Rugged Eastern Area of the Cumberland Plateau (as defined by Braun 1950) in eastern Kentucky. According to maps in Campbell et al. (1993), about 40 populations of S. wasiotense are known.