woolly thistle

(noun) biennial Eurasian white hairy thistle having pale purple flowers; naturalized in North America. Synonyms: cotton thistle, woolly thistle, Scotch thistle, Onopordum acanthium, Onopordon acanthium.

(noun) thistle of western North America having white woolly leaves. Synonyms: woolly thistle, Cirsium flodmanii.