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 and includes considerable variation in leaf hair and gland density.
Nesom (2020) split this variety into multiple species, some of which might warrant recognition at some rank. Het. hispida (Hook.) Nesom occurs in the western prairies into the Rocky Mts. Het. orovillosa Nesom occurs in SW Oregon south to the southern Sierra Nevadas in California.
Last revised 1 May 2025 by J.C. Semple
© 2025 J.C. Semple, including all photographs unless otherwise indicated
1-4. Heterotheca villosa var. minor. 1. Habitat along RR, Semple & Shea 1936, Saskatchewan (H. hispida (Hook.) Nesom. 2. Small plant, Semple et al. 4715, Shasta Co., California (H. orovillosa Nesom). 3. Upper stems and heads, Semple et al. 9314, Plumas Co., California (H. orovillosa Nesom). 4. Upper leaves and heads, Semple & Zhang 10417, Fremont Co., Wyoming. 5. Habitat of 'wisconsinensis' morph, Semple 8845, Adams Co., Wisconsin (H. wisconsinensis (Shinners) Shinners). 6. 'wisconsinensis' morph, S 8845.