Heterotheca villosa var. minor (Hook.) Semple is the most common and widely distributed race in the species.  It has less-hairy, more-glandular leaves with gland and hair densities being variable.  It has been treated as H. villosa var. hispida (Hook.) Harms, but the name does not have nomenclatural priority at varietal rank. Many other names also belong in synonymy. The variety hybridizes with all other varieties.  If this variety did not exist, then treating all the other varieties as separate species might be reasonable.  Var. minor is the "glue" that holds the hold entire complex together in a single species.

Heterotheca villosa var minor Fig 46 Semple 1996