This largely Appalachian taxon has been confused with patens, but it is generally considered to be a distinct species (Jones 1983). Within the central Bluegrass regions, it is known only from a few sites in CLAR and FAYE; see also old colls. of P. Peter (MICH) and C.W. Short (CM). Withn Appalachian regions patens tends to be somewhat glandular, with relatively short inflorescence branches and disc corollas often purple-tipped. These characters might suggest some intergradation with phlogifolium; both taxa are tetraploids (2n = 20). Better documentation of true phlogifolium is needed along the western margin of its range. B reported the species from HART, but no coll. has been located. A coll. of C.W. Short (MO) from "barrens of Ky." appears to be phlogifolium, but the leaves are less elongated than typical plants and stems are less glandular.