[1][3] The plants are native to the Mediterranean regions of Europe,[4] North Africa, and the Middle East.

that the active flavanoid-lignan (flavanolignan) group of constituents, called silymarin, contained only in the seed shell has liver-protective and regenerative properties, as well as antioxidant effects.

They have large, disc-shaped pink-to-purple, rarely white, solitary flower heads at the end of the stem.

[7] The two species hybridise naturally, the hybrid being known as Silybum × gonzaloi Cantó, Sánchez Mata & Rivas Mart.

Milk thistle is believed to give some remedy for liver diseases (e.g. viral hepatitis) and the extract, silymarin, is used in medicine.

"[12] Milk thistle has been reported to have protective effects on the liver and to greatly improve its function.