"It is native to warm temperate and tropical regions in southern Eurasia and Africa. It has been unintentionally introduced to North America and Australia. An aggressive and hardy invasive species, T. terrestris is widely known as a noxious weed because of its small woody fruit – the bur – having long sharp and strong spines which easily penetrate surfaces such as the bare feet or thin shoes of crop workers and other pedestrians, the rubber of bicycle tires, and the mouths and skin of grazing animals." (Wikipedia)