Canadensys: University of Alberta Vascular Plant Herbarium (ALTA-VP)
Canadensys, operated from the Université de Montréal Biodiversity Centre
"81513 - Cirsium pitcheri (Torr. ex Eaton) Torr. & A. Gray, University of Alberta Vascular Plant Herbarium." University of Alberta Museums Search Site, https://search.museums.ualberta.ca/12-151267. Accessed 28 Feb. 2025.