There has been some confusion in Ky. between this widespread northeastern species and serpentarius or other species, but records of albus mapped here are mostly confirmed. Records from the northern Bluegrass are old (KENT: Greenert in 1927 at GH) or unverified (BOON: Bryant 1981); the species is known from nearby counties in se. Ind. and sw. Ohio (K). There is also a verified 1840 coll. of C.W. Short (GH) from "Barrens of Ky." N. albus is similar to trifoliolatus and serpentarius, but usually has a distinctively deep reddish-brown ("cinnamon") pappus (versus stramineous or pale brown); 2n = 32 (versus 16). N. trifoliolatus is distinct in its primary involucral bracts which are as long as the pappus (versus shorter), and its outer ones ("calyculi" of FNA 19) which are deltoid to ovate (versus deltoid to lanceolate or setaceous). The more southern serpentarius differs from both of these northern species in its pubescent involucral bracts (versus glabrous); With leaves alone, distinction may be difficult or impossible, but albus often has has hastate lower leaves that persist until flowering. These species may all be short-lived monocarpic perennials, but further studies of life-history are needed.