Milk Thistle

Silybum marianum (L.) Gaertn.

Milk thistle is a robust annual or biennial plant with prickly, white-marbled leaves and purple flower heads.

The ripe fruits are used to make herbal preparations. They contain a distinctive complex of active ingredients known as silymarin.

Profile

  • German name: Milk Thistle
  • Botanical name: Silybum marianum (L.) Gaertn.
  • Family: Asteraceae
  • Plant type: An annual or biennial herbaceous plant
  • Height: About 60 to 150 centimeters
  • Flowering period: Usually June through September
  • Part of the plant used: Ripe Fruit
  • Special feature: White-marbled, spiny leaves

The milk thistle first forms a large rosette of leaves. Its glossy green leaves are deeply lobed, bear sturdy thorns, and are crisscrossed by striking white veins.

A branched stem grows from the rosette. At its tips are spherical flower heads with reddish-purple tubular flowers and spiny bracts.

After flowering, hard, elongated fruits develop, each with a ring of white hairs. Botanically speaking, these are fruits, although in everyday language they are often referred to as seeds.