Plants of the San Marcos Foothills Preserve
Silybum marianum (Milk Thistle)
Uncommon, native, perennial shrub found in coastal sage-scrub plant community, but also on the edges of oak woodland. Flowers are yellow (aging red). Blooms in spring. Previous scientific name: Lotus scoparius.
Silybum marianum (Milk Thistle). NON-NATIVE. Pictured in summer.
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 spring.
Silybum marianum (Milk Thistle). NON-NATIVE. Pictured in summer.
Silybum marianum (Milk Thistle). NON-NATIVE. Pictured in Winter.
Silybum marianum (Milk Thistle). NON-NATIVE. Pictured in Winter. Note developing seedling.
Silybum marianum (Milk Thistle). NON-NATIVE. Pictured in spring.