Common non-native herb found in disturbed areas. Flowers are red-violet. Blooms in spring to summer. Leaves have distinctive white veins.

Silybum marianum (Milk Thistle). NON-NATIVE. Pictured in Winter.

Silybum marianum (Milk Thistle) seedling (left) compared to Carduus pycnocephalus (Italian Thistle) seedling (right). Note that Milk Thistle has white ("milky") veins, true leaves on Italian thistle seedlings tend to developed asymmetrically (i.e. one leaf larger than the other).

Silybum marianum (Milk Thistle). NON-NATIVE. Pictured in Winter. Note developing seedling.

Silybum marianum (Milk Thistle). NON-NATIVE. Pictured in spring.

Silybum marianum (Milk Thistle). NON-NATIVE. Pictured in spring.

Silybum marianum (Milk Thistle). NON-NATIVE. Pictured in summer.

Silybum marianum (Milk Thistle). NON-NATIVE. Pictured in summer.