Cirsium clavatum of FNA (vol. 19, 2006) includes the following species that are separately recognized by Kartesz 1999: C. araneans and C. osterhoutii (in C. clavatum var. osterhoutii), C. griseum, C. laterifolium, C. modestum, and C. scapanolepis (in C. clavatum var. americanum).

The FNA records already existed as provisionals, and were made standard.

The formerly standard records, as listed above were made nonstandard and then inactivated (C. araneans and C. osterhoutii, C. griseum, C. laterifolium, C. modestum, and C. scapanolepis).