This is a largely Ozarkian species that is usually considered to be a "casual adventive" in more eastern states (F); also, it has been confused with the southern Appalachian P. maculata Wood (W). P. gilioides differs from purshii and allies as follows (Levy 2020; W): carpels with 4 ovules (versus 2); and corolla lobes with denticulations only < 1 mm (versus fimbriations mostly 0.4-1.5 mm long). It is also close to the largely Ozarkian P. hirsuta Nutt., and it may have originated from hybridization; in hirsuta, corolla lobes are entire or nearly so (Y). A plant suggesting gilioides or hirsuta was collected in 2003 from MCRE (EKY), at the end of Harley-Coffee Road [SW of Wiborg] by D.F. Coffee with D. Stephens; but the coll. has not yet been determined or accessed, and no further plants could be found at the site (R. Jones, pers. comm.); the plant may have been a waif from hay for horses. At Mantle Rock (LIVI), near Grassland (EDMO), and perhaps on other sandstone outcrops in the Shawnee Hills, purshii-like plants are locally abundant but the dry sandy habitats are more typical of gilioides. P. gilioides has been verified from Short Mountain in Cannon Co. in c.Tenn. (F. Levy, pers. comm.), and from Saint Clair Co. in s . Ill. (K).