This annual member has spiny leaf margins, and the base of the leaves have rounded lobes, which clasp the stem. Sow thistle is found in disturbed ground and waste areas. The sow thistle belongs in the daisy family.
Perennial sow thistle is similar to the annual species, but the bases of the clasping leaves are pointed rather than rounded.

Photo by Gary Huntzinger
Rutgers NJAES Cooperative Extension

Photo by Gary Huntzinger
Rutgers NJAES Cooperative Extension

Photo by Gary Huntzinger
Rutgers NJAES Cooperative Extension

Photo by Dr. John Meade, weed scientist emeritus
Rutgers NJAES Cooperative Extension