This was recently described from a few counties in nc. Tenn and CUMB in sc. Ky. (Ch+; Estes et al. 2012). It is rare on mesic to subxeric, thinly wooded limestone bluffs, ledges and talus slopes near the Cumberland Rv. or its major tributaries. G. cumberlandensis is distinguished from canadensis as follows: plants taller (5-8 dm versus 1.5-4 dm), with thicker stems (4-5.2 mm versus 0.8-2.5 mm at middle); hairs at mid-stem mostly shorter (ca. 0.2-1 mm versus 0.4-2 mm), more diverse with many short glandular hairs (versus sparse); leaves larger (mostly 6-8 x 3.5-7 cm versus 1.8-4 x 1.2-2.2 cm), less deeply cut (coarsely toothed to shallowly trilobed versus deeply lobed to 60-80% cleft); corollas longer (17-21 mm versus 15-17 mm), with a wider orifice (2.5-3.5 mm versus 2-2.5 mm).