any of about 1,200 species of annual, biennial, and perennial herbs, shrubs, trees, and climbers comprising the genus Senecio of the family Asteraceae, distributed throughout the world. Some species are cultivated as border plants or houseplants, and many species contain alkaloids that are poisonous to grazing animals. The effect is cumulative.
A mature plant
Research is currently underway to find an antidote to ragwort poisoning. The best ways to control ragwort is to let sheep graze it in the spring and to encourage the establishment of the cinnabar caterpillar colony on the site.
A tasty treat for the cinnabar caterpillar