Milk thistle

Silybum marianum

Asteraceae

Spiny purple thistle whose seeds are the classic liver trophorestorative.

Supplement. Seeds are the official part.

Parts used: Ripe seed
Traditional notes: After liver strain · Dyspepsia with fat intolerance · Support alongside some medications (clinician-directed)
Grow · USDA 6b: Annual or biennial, USDA 6–9 Direct-sow in autumn or early spring. Gloves for every later job. In work: Mar · Apr · May · Jun · Jul · Aug
Harvest: Cut heads when purple fades and white pappus shows; dry in paper bags.

Gloves. The whole plant is armed.
Seed is the crop — bag the heads before they parachute.
One plant is plenty. It is a generous self-sower.

Safety

Hormone-sensitive conditions — theoretical estrogenic effect Asteraceae allergy

Lore

Dioscorides already has a thistle for the liver. The white-splashed leaves were said to be Mary’s milk. Silymarin, the seed extract, is one of the few herbal products a modern liver clinic will actually discuss.

The Herbarium — a teaching catalog, not a clinic. Traditional use is history, not a prescription. USDA 6b dates are a week either way, not a promise. Do not eat, drink, or harvest a plant you cannot name.