Heterotheca villosa var. nana (A. Gray) Semple is a less-hairy more glandular race native to the western Great Plains and into the Rocky Mts. It has been treated as H. villosa var. horrida (Rydb.) Harms, a name that does not have nomenclatural priority, and as C. horrida Rydb. It is diploid (2n=18). Semple (1996) concluded that there were too many intermediates with other races of the H. villosa complex including var. foliosa and var. minor to warrant species rank for the taxon.
Nesom (2020) treated the race as H. hirsutissima (Greene) Nesom based on Chrysopsis hirsutissima Geene and listed Chrysopsis villosa var. minor Hook. as a synonym. Again, polygenomic DNA research is needed to determine how best to treat this member of the H. villosa complex.
Last revised 8 May 2025by J.C. Semple
© 2025 J.C. Semple, including all photographs unless otherwise indicated
1-2. Heterotheca villosa var. nana. 1. A lonely plant on cliff face, Royal Gorge, Colorado; an atypical habitat. 2-3. Habit on prairie and flowering shoot, Semple & K. Shea 2222, Arapahoe Co., Colorado. 4. Heads, Semple et al. 5768, Moffat Co., Colorado.