Bull Thistle is a member of the Sunflower
height and has dark green, lance shaped, spiny leaves leaves which clasp
the stem of the plant and grow to 6 inches in length. The plant grows
along road sides and in fields.
Bull Thistle is not native to
Arizona and is considered a weed.
Bull Thistle blooms
between June - September and produces purple to pink
flowers to 2 inches in width. Flowers are follwed by "thistledown" -
small seeds with covered with fluff. This type of seed is called an "achene."
The Bull Thistle is a biennial plant, which means it lives for two
years and then dies. The first year it grows a rosette, a cluster of
leaves near the ground. The second year it grows flowers and fruits,
spreading seeds before it dies.