Onopordum acanthium, commonly known as Scotch thistle, is a species of thistle native to Europe and western Asia. Its distinctive purple flowers and prickly leaves make it a recognizable plant. Some synonyms for Onopordum acanthium include cotton thistle, woolly-headed thistle, and giant cotton thistle. These synonyms refer to the plant's appearance and texture. Another synonym, buffalobur, is a nod to the plant's status as an invasive species in North America. Whatever name it goes by, Onopordum acanthium is a hardy plant that can thrive in a variety of environments, making it both loved and hated by gardeners and farmers alike.