This northeastern taxon can probably be considered widespread in the state, but there has been much taxonomic confusion with argutus and allied taxa. Typical pensilvanicus, as interpreted by F and mapped here, includes the closely related species R. abactus Bailey (POWE), R. philadelphicus Blanch (ESTI, FAYE, PULA, RUSS), and R. ostryifolius Rydb. (CAMP, KENT). This complex will be studied further when MM's colls. are processed at APSC. Plants with leaf margins irregularly deep-lobulate have been tentatively segregated as laudatus (see under that name). Plants with more numerous large foliaceous bracts have also been segregated by some authors, but it is not clear in Ky. if these should be grouped with frondosus (B, F) or pensilvanicus (Gl, St). Moreover, Widrelechner (1998; see also, Ladd & Thomas 2015) interpreted some common old-field blackberries of this group in Iowa, Missouri and some adjacent states as R. ablatus Bailey, which F included under jugosus (see notes under argutus).