Canadensys: University of Alberta Vascular Plant Herbarium (ALTA-VP)
Canadensys, operated from the Université de Montréal Biodiversity Centre
"136175 - Cirsium wheeleri (A. Gray) Petr., University of Alberta Vascular Plant Herbarium." University of Alberta Museums Search Site, https://search.museums.ualberta.ca/12-159665. Accessed 19 Apr. 2025.