This occurs mostly in mesic to subxeric woods of Appalachian regions or nearby, but it also extends west to the Shawnee Hills and Ozarks (FNA 23, K). C. virescens is similar to swanii, and occasional colls. may appear intermediate (e.g., from BARR at WKY). Some older treatments included swanii (e.g. Anderson 1924; M). However, virescens is now generally accepted as a distinct species; 2n = 60 (versus 54 in swanii). Moreover, swanii is probably closer to hirsutella based on recent genetic analysis (Smith & Waterway 2008b; T.W. Smith, pers. comm.).