Bull Thistle,  Cirsium vulgare
Asteraceae or Sunflower Family

Plant Tall erect, viciously prickly, but very pretty plant.  The leaves, flower heads and stems, are covered with spines.  Leaves deeply and irregularly cut and lobed, spiny at lobe tips,.  Flower heads typical of a thistle, about 2 inches tall, with a multitude of long-petaled purple flowers.  Blooms in the summer

Alien weed of fields, roadsides and waste places.  Occasional along the bike path, along Wildwood Drive and around the butterfly meadows.

The native field thistle (Cirsium discolor) has a little bit smaller flowers, white wool on the undersides of the leaves, and no spines on the stems.