"Species Details - Matteuccia struthiopteris (L.) Todaro var. pensylvanica (Willd.) C. V. Morton, University of Alberta Vascular Plant Herbarium." University of Alberta Museums Search Site, https://search.museums.ualberta.ca/g/1-7132/12-18601. Accessed 04 Sep. 2024.
There are 43 specimens of this Species.