Petasites nivalis subsp. hyperboreus (Rydberg) J. Toman

Petasites nivalis subsp. hyperboreus (Rydberg) J. Toman is a synonym sensu FNA Ed. Comm., 2006b of:

Petasites frigidus (Linnaeus) Fries var. frigidus, an accepted variety name sensu FNA Ed. Comm., 2006b.