The central native range of polylepis is considered to be somewhat more southern and western than aristosa (FNA 21; Ladd & Thomas 2015). The two taxa appear to intergrade, and some authors have suggested varietal status (St, Cr) or complete combination, as in Ark. and Mo. (Y), but a range-wide analysis is still needed. B. polylepis may be even less shade tolerant (Cr) and more concentrated on wet ground (FNA 21). B. polylepis differs from aristosa in its "calyculi" (bracts or bractlets around phyllaries), which are usually more numerous (ca. 12-21 versus 8-12) and broader (ca. 8-12 mm versus 5-7 mm); also, its disc florets are usually more numerous (ca. 60-100 versus 20-40); and its inner seeds (cypselae) are usually longer (7-8 mm versus 5-7 mm), with appended pappi (if developed) retrorsely barbed (versus antrorsely or retrorsely). Some plants with awns retrorsely barbed were transferred to aristosa as var. retrorsa (Sherff) Wunderlin (1972), but appropriate nomenclature remains uncertain. Coreopsis involucrata Nutt. may be the earliest basionym within the whole complex.