Haplopappus carthamoides subsp. rigidus (Rydberg) H.M. Hall

Haplopappus carthamoides subsp. rigidus (Rydberg) H.M. Hall is a synonym sensu FNA Ed. Comm., 2006b of:

Pyrrocoma carthamoides Hooker var. carthamoides, an accepted variety name sensu FNA Ed. Comm., 2006b.