About Cirsium griseum (Rydb.) K.Schum.
Cirsium clavatum, commonly called Fish Lake thistle or fringed thistle, is a North American plant species belonging to the tribe Cardueae in the Asteraceae family. It is native to the western United States, specifically found in Wyoming, Colorado, Utah, Arizona, and New Mexico. Cirsium clavatum is a biennial or perennial herb that grows up to 100 cm (40 inches) tall, blooms once, then dies. Its leaves have thin spines along their edges that are much smaller than the spines of related species. The plant produces several to many flower heads, which contain white or pale pink disc florets but no ray florets. Three varieties are recognized: Cirsium clavatum var. americanum (A.Gray) D.J.Keil occurs in Colorado, Utah, and Wyoming; Cirsium clavatum var. clavatum occurs in Colorado and Utah; Cirsium clavatum var. osterhoutii (Rydb.) D.J.Keil occurs in Colorado.
