Bull thistle (Cirsium vulgare), also sometimes called ... equally spiny stalks topped with purple flowers. Later, fluffy white seed heads form. You've probably spotted this thistle in well-used ...

Thistles or Cirsium may be best known for their showy purple flowers and pink flowers, in addition to their prickly foliage. But these perennials are also important for pollinators, as well as a ...