Cirsium undulatum is a species of thistle known by the common names wavyleaf thistle and gray thistle. It is native to much of central and western North America from British Columbia east to Manitoba and south as far as the State of Durango in Mexico. Wavy-leaf thistle is a perennial herb up to 79 cm in height. The leaves are very wavy along the edges and usually cut into shallow toothed lobes. The inflorescence holds one or more flower heads, each up to 5 cm long and wide. Flowers are purple, pink or sometimes white.
Seeds are easily collected from dried seed heads. Pluck gently, ensuring seed is removed.
The hillside south of Mesa Reservoir