Mapping remains tentative, since variation within this species deserves further study; see W for recent treatment. Var. erwinieae was originally recognized in the mountains of nw. S.Car. and sw. N.Car. (W); the few potential colls. from mountains of Tenn., Ky. and Va. (K) need closer examination. Southern Appalachian plants of obliqua with 2n = 56 (tetraploid) may represent var. erwiniae (Nelson et al. 1998). In the rest of the species, 2n = 84 (hexaploid); other species of Chelone are all diploid. Appalachian colls. of obliqua in Ky. are probably referable to var. erwiniae, following Pennell (1935), but this taxon has not been recognized in some recent treatments. It may be distinguished from typical obliqua as follows (W): lower corolla lobes mosly 12-15 mm long (versus 15-19 mm); mid-cauline leaves mostly 8-20 cm long (versus 5.5-8 cm).