Bull thistle is a true biennial. It forms a rosette of leaves the first year and then sends up a flowering stalk the next year. Like other thistles it has sharp spines on stem and leaves. The flower is blue and quite large. Normally a weed of untilled fields.
![Photo of Bull Thistle](images/large/bullthistle-full.jpg)
Photo by Dr. John Meade, weed scientist emeritus
Rutgers NJAES Cooperative Extension