Although this species was first described in 1981, from Ky., it is now known from disjunct populations across most southeastern states (Case et al. 1998; FNA 26, K,W). In addition to its distinct cluster of sites along the western edge of the Appalachian Plateaus in Ky. and n. Tenn, it occurs in or near the Ouachita Mts. (Ark., Okla.) and in several parts on the Coastal Plain (Tex., La., Miss., Ala., Ga., Va.). There is a poor coll. from BALL (MUR) on the Coastal Plain in Ky. that was det. as "cf. C. kentuckiense" by J.T. Atwood. Several records of Reed (1981) have no known colls. Some populations may have been looted on occasion by horticultural collectors, e.g. along Triplett Creek in ROWA, and Negro Creek in WHIT. The virtual absence of this species from the Red River watershed (MENI, POWE, WOLF) might reflect such looting. C. kentuckiense is distinct from typical pubescens in its larger flowers (FNA 26, W), the dorsal sepal 3.5-5 cm wide (versus 1.1-2.9 cm), the lip 45-65 mm long (versus 35-58 mm), with a broader "cavernous" orifice 27-45 mm long, 27-37 mm wide (versus 5-17 x 10-23 mm), less forwardly projected as a "slipper", pale yellow or "ivory" (versus deep yellow), and usually appearing in mid- to late May (versus late April to early May). Plants are mostly 50-80 cm tall (versus 20-50 cm). Hybridization is suspected in Ark. and Va.; it may be expected elsewhere (e.g. iNaturalist image of :"blacklionbrewer" from POWE in May 2023). Chromosome number is consistent across the genus (2n = 20) and several natural or artificial hybrids are known (Burch 2015). Curiously, C.W. Short (NY) did make a coll. of this species from Ky. during ca. 1840, but it remained identified as pubescens until corrected by M. Pace in 2016. Rafinesque (1828, 1833; Merrill 1949) noted several varieties of his "luteum" [= pubescens] and several related species that he named with brief inadequate descriptions; it is likely that one of his names applied to kentuckiense, but no supporting colls. have been located (FNA 26)..