Milk Thistle, aka Silybum Marianum, is an annual in the Asteraceae family that grows three to seven feet tall with lettuce-like leaves and spikey, purple flowers. The Milk Thistle plant has been used for centuries as a food and for its healthful properties. Milk Thistle Seed has a long tradition of use in western herbalism and is typically decocted as a tea. It can also be powdered for tinctures or encapsulated.