Ynghylch

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. It is sometimes considered a problematic plant in paddocks and pastures, where it can be harmful to livestock if eaten. It is not usually such an issue in gardens or on waste ground. In fact, it is a very beneficial plant for many insects. Ragwort 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 is a biennial, flowering in its second year from June to November.