Silybum marianum - This annual is famous for its medicinal seeds, which have been used to treat the liver. The leaves have large green and white patches and are very ornamental. Small bushes form into early summer and are topped with large purple flower pods. The seed is collected once the pods are dried and form fluffy tops. This plant is very easy to control and simple to remove, there is no tap root. We like to encourage it to grow in areas of poor soil, and it thrives with very little care. Direct seed in spring or fall in milder climates.