This is centered in central and southern Appalachian regions, but with other scattered localities across most southeastern states (K). Despite occurring in diverse habitats, populations are often fragmented and threatened by excessive disturbance, herbivory or pathogens (Fletcher et al. 2001, Hill 2007, Barrett 2017, Dunlap 2023). In Ky. it has been recorded from Black Mt. in the east and from some swampy lowlands in the west. Also, intervening localities have recently been discovered on the Cumberland Plateau: along banks of the Big South Fork (MCRE at EKY; also Tenn.), and on uplands (LAUR at EKY; Libby et al. 1997). There has been some confusion with the closely related midwestern species, michiganense. L. superbum is best distinguished from that species and canadense (Adams 1981; FNA 26, F, W) by its longer anthers (14-26 mm versus 6-13 mm), pale green styles (versus as brightly colored as tepals), sepals with 2 abaxial ridges, and somewhat triangular buds in cross-section (versus rounded). Leaves are smooth or with low rounded papillae on margins and nerves below; the other species usually have minute spicules. L. superbum tends to be taller (1.2-2.8 m versus 0.5-2 m), with larger flowers on average, and it tends to flower later, mostly in early Jul to early Sep (versus mid-Jun through Jul). However, cultivated plants in central Ky. (V. Holmberg, pers. comm.) send up shoots in early to mid-April, about two weeks earlier than michiganense (mid- to late April); in western Ky. (MCRA), shoots appear as early as mid-March (Dunlap 2023). There may be intermediates between these two species in western regions of Ky. For example, the coll. from HARD (KY) has been determined as michiganense (Cranfill 1991), but it has large anthers and smooth leaves that suggest superbum. Hybridization among related species of Lilium is often indicated; 2n = 24 in all reports from eastern species. However, hybrids of superbum and michiganense are not well documented in the literature.