Bull thistle starts out life as a prickly ground-hugging rosette that, in the summer, puts out tall, equally spiny stalks topped with purple flowers. Later, fluffy white seed heads form.

Like many other biennial invasives, bull thistle is able to produce a large seed bank that can remain viable for up to 10 years! As a result, the plant can easily spread and form dense stands in ...

unlike the leaves and unlike bull thistle and European marsh thistle pink, white, or lavender-colored flowers with flat bracts and pointed tips that bloom in June seed are fluffy, white tufts of hair ...