Ragwort is the name of many species of plants with flat-topped clusters of small yellow-rayed flowers. The common ragwort of Europe grows to just over 3 feet (1 meter) high. It has deeply lobed, featherlike leaves and grows on sand dunes and other dry grassy areas. Oxford ragwort, a southern European plant, was first grown in England in the Oxford Botanic Gardens. Groundsel, a common weed, is a kind of ragwort. Some ragworts with showy flowers are cultivated and are best known by their Latin name Senecio.