This is known mostly from base-rich soils in e. Tex. to Mo., and in or near the Piedmont of Ala. to Va. The species has been reported from Ky. (including CARL, CRIT, MARS and WARR) based largely on colls. of R. Athey and M. Medley, but it is not verified (M). Identification has been difficult due to inadequate colls. and varied treatments, with obliqua often confused; figures of flowers appear switched in Gl but not corrected in Holmgren et al. (1998). Based on more reliable treatments (F, Y, W), the corolla lobes of decipiens are usually "dark maroon", that is brownish-purple to almost black (versus usually "rose to light maroon" in obliqua), but this may not be a reliable difference in some cases. Corolla lobes tend to be relatively large: (7)11-15(18) mm x 3-6 mm (versus 6-15 x 1.5-2.5 mm); widest at or above the middle and obtuse (versus more linear, widest at base, acute), with L/W mostly 2-4 (versus 4-6). See further notes under obliqua and carolinensis; in some features, decipiens appears intermediate. Moreover, Drapalik (1969; and in annotations at US etc.) identified several colls. across southeastern states as intermediate between decipiens and carolinensis.