Canada Thistle, Canadian Thistle, Creeping Thistle: Cirsium arvense (Cirsium arvense var. arvense, Cirsium arvense var. horridum, Cirsium arvense var. mite) -
Cayuse Thistle, Edible Thistle, Indian Thistle, Macoun's Thistle: Cirsium edule var. edule (Synonyms: Carduus macounii, Cirsium edule var. macounii, Cirsium hallii, Cirsium macounii) -
Fewleaf Thistle, Remote-leaved Thistle: Cirsium remotifolium (Synonyms: Carduus remotifolius, Cirsium callilepis, Cirsium callilepis var. oregonense, Cirsium remotifolium ssp. remotifolium, Cirsium remotifolium var. odontolepis, Cirsium remotifolium var. remotifolium, Cirsium remotifolium var. rivulare) -
Bull Thistle, Common Thistle: Cirsium vulgare (Synonym: Carduus vulgare) -