As sow thistle can grow up to 1 m tall, it can be quite a competitive weed ... The lobes in each leaf of prickly sow thistle do not tend to cut in so close to the midrib of the plant as in sow thistle ...

Scotch thistle ... around the leaf margins. The rest only have spines around the margins. As with all thistles, seed heads are a collection of florets, and each seed is attached to a pappus which ...

European marsh thistle frequently invades fens, wetlands, and disturbed sites such as roadside ditches. Identifying features include: typically grows 2-7 feet tall leaves are alternate with deeply ...