Bull Thistle

Cirsium horridulum

Family: Asteraceae

Plant Description: Biennial or perennial to 1 m high with spiny leaves 15-30 cm long. Heads solitary or few together, 4.5-6 cm high discoid. Corolla pink, lavender, purple, or white.

Plant Trivia:

Field Identification:

Occurrence: Fairly frequent on deep sands in prairies an openings.

Bloom Period: March-June

Plant Use:

Key to species of Cirsium:

  1. Heads subtended by a whorl of spiny bracts…………………..C. horridulum

Heads not bracted……………………………………………………………...C. texanum