This is a very large and incredibly diverse genus. It contains annuals, biennials, herbaceous perennials, succulents, climbers, shrubs and small trees. Its members also include the invasive weeds groundsel and ragwort.
There are over 1000 species worldwide, growing in a wide range of habitats from wasteland and seashores to marshes and woodland.
Conditions required vary widely with the species. Many grown in gardens do best in sun, with free-draining soil.