Xanthium spinosum is a species of flowering plant in the aster family known by many common names, including spiny cocklebur, prickly burweed and Bathurst burr. It is known worldwide as a noxious weed that grows in many types of disturbed habitat. Its original native range is not known but it may have come from South America, possibly from Chile. Xanthium spinosum is an annual herb producing a slender stem up to 1 metre (3 ft 3 in) tall or slightly taller. It is lined at intervals with very long, sharp, yellowish spines which may exceed three centimeters in length and may divide into two or three separate spines.