: Blooming occurs from June through October. The flower heads are topped with yellow florets and surrounded by stiff, sharp spines arranged in a star-like pattern.
: The plant typically grows between 1 and 3 feet tall, featuring gray-green to blue-green stems covered in fine, white cottony hairs. barnaby's thistle
Barnaby's Thistle is considered a in many regions, including much of the western United States and Australia, due to its aggressive growth. : Blooming occurs from June through October