This globally threatened annual or short-lived perennial is known only from under sandstone cliffs of the Cumberland Plateau in n. Tenn. and se. Ky. The plants discovered by M. Medley and J. Thieret during 1984 along Rock Cr. in sw. MCRE (KNK) have not been refound, despite several attempts. However, M. Evans and A. Risk discovered a good stable population during 1991 and 1994 close to the Big South Fork in n. MCRE (EkY, MDKY). Recovery is currently being attempted on Daniel Boone National Forerst (D. Taylor, pers. comm.).