Cirsium clavatum (Fish Lake thistle) is a North American species of plants in the thistle tribe within the sunflower family. The species is native to the western United States, the States of Wyoming, Colorado, Utah, Arizona, and New Mexico.Cirsium clavatum is a biennial or perennial herb up to 100 cm (40 inches) tall, blooming only once before dying. Leaves have thin spines along the edge, much smaller than those of related species.