Canadensys: University of Alberta Vascular Plant Herbarium (ALTA-VP)
Canadensys, operated from the Université de Montréal Biodiversity Centre
"85381 - Cirsium arvense (L.) Scop. fo. albiflorum (E. L. Rand & Redfield) Ralph Hoffm., University of Alberta Vascular Plant Herbarium." University of Alberta Museums Search Site, https://search.museums.ualberta.ca/12-151017. Accessed 03 Apr. 2025.