The daisy-like, yellow flower heads of Common Ragwort may be pretty enough to the casual observer, but they belie the poisonous nature of this plant. Renowned as a weed of paddocks and pastures where it can be harmful to livestock, it is not usually such an issue in gardens or waste grounds. In fact, it is the foodplant of the black and red Cinnabar Moth: sometimes its black- and yellow-barred caterpillars cover the plant, totally stripping the leaves. Common Ragwort flowers from June to November.