This midwestern taxon has been re-evelated to species status in W; see also Folk (2015). However, it has been considered by some authors (e.g. Wells 1984, Cr, FNA 8) to have resulted from introgression with the more western species, H. richardsonii R. Br. It was not recorded from Ky. by Wells, but the identification of colls. mapped here is confirmed. There is also an unmapped coll. from MADI (BEREA) that is misleading; it comes from cultivation of buried seed, "with forced flowering" (R. Thompson & Wade #87-2033), and its origin is unclear. Compared to typical americana, hirsuticaulis differs as follows (W): petioles densely hirsute (versus glabrous to sparsely hirsute); free hypanthium 1.1-1.9 mm long with mean 1.5 mm (versus 0.6-1.5 mm with mean 1.1 mm),