Ox-eye daisy (Chrysanthemum leucanthemum L.)
Ox-eye daisy, a member of the aster family, is a perennial that was introduced to the United States as an ornamental plant. It grows 1-3 feet tall with flowers that have white ray florets surrounding numerous tiny yellow disk florets. It can be distinguished by oblong, alternate leaves with distinct rounded teeth along the edges, and a clump of rosette leaves at the base. Leaves become progressively smaller up the stem.
Ox-eye daisy is sometimes mistaken for a wildflower, but it can be harmful to the native ecosystem. It is illegal to plant ox-eye daisies in Wyoming, but some recommended substitutes for gardens are the Shasta daisy or blanket flower.