Senecio is a large genus of plants, with over 1,000 species dispersed around the world. Some are lovely, and others, like groundsels and ragworts, are noxious weeds. There are about 100 succulent Senecios. There are some large shrub varieties, but many are small, trailing plants or spreading ground covers. Their leaves are thick and fleshy and can be deep green, bluish, or even striped. Senecio succulent leaves vary widely in shape. Some are round, some are banana-shaped, and some stand upright. Senecio flowers form in clusters on long stems. The flowers persist for weeks—their shapes include red or white spires and yellow daisy-like flowers, but it's the foliage that interests most gardeners.