F indicated that this taxon is largely northeastern, but "cult. and locally spread elsewhere." Its native range may extend south only to W.Va. (unpublished maps of H.A. Davis and M. Medley). R. bellobatus differs from pensilvanicus (F) in its cylindric, racemose inflorescence (versus somewhat corymbose), which is slightly glandular, prompting Widrlechner (1998) to include it within alumnus (see above). It was reported from GRAV and MARS by Davis et al. (1969), but their sources need to be checked. An allied taxon, R. mollior Bailey, is centered in the Ozark region (St) but not reported from Ky.