S cotch thistle is a biennial that grows up to 8 feet tall.
Stems have broad, spiny wings.
Leaves are large, spiny, and covered with fine dense hair, giving a grayish appearance. Flowers are violet to reddish. It can be found along waste areas and roadsides. It is an aggressive plant and my form stands so dense that they are impenetrable to livestock. Scotch thistle can be controlled with herbicides.