The purple flower heads may look pretty, but don't let that fool you. Milk thistle (Silybum marianum) can be a pain if it's growing in your yard. It's non-native and can be an invasive plant ...

The basal foliage of the Italian eryngo is evergreen in milder climates and looks rather like leathery thistle leaves. In summer, the well branched stems carry small egg-shaped flower heads ...

but not as strongly as in variegated thistle (Silybum marianum). Each flower head is up to 2 cm long and about 1.5 cm wide, and there are usually clusters of these heads at the ends of each stem, with ...

As livestock don’t like eating thistles, it flowers freely in pastures ... The root will not regrow if these buds are removed. Seed heads of Scotch thistle often appear distorted late in the season ...