"Species Details - Petasites frigidus (L.) Fries var. sagittatus (Pursh) Cherniawsky & R. J. Bayer, University of Alberta Vascular Plant Herbarium." University of Alberta Museums Search Site, https://search.museums.ualberta.ca/g/1-19707/12-164652. Accessed 12 Dec. 2024.
There are 95 specimens of this Species.