Senecio is a large and diverse genus in the Asteraceae family. It is one of the largest genera of flowering plants with over 1200 species with a global distribution. The flowers are usually yellow, but can rarely be white, green, purple or blue. Within the genus are annuals, trees, shrubs, and the horrible weed groundsel (S. vulgaris), which is probably the member of the genus with the widest distribution here in Iceland. It also includes some hardy perennials that make nice garden plants.