woolly thistle vs Onopordon acanthium

woolly thistle and Onopordon acanthium both are nouns.

Word	Noun	Adjective	Verb	Adverb
woolly thistle	Yes	No	No	No
Onopordon acanthium	Yes	No	No	No

As nouns, woolly thistle and Onopordon acanthium are synonyms defined as:

woolly thistle and Onopordon acanthium: biennial Eurasian white hairy thistle having pale purple flowers; naturalized in North America

Other synonyms of woolly thistle include cotton thistle, Onopordum acanthium, Scotch thistle.

woolly thistle (noun)	Onopordon acanthium (noun)
thistle of western North America having white woolly leaves	biennial Eurasian white hairy thistle having pale purple flowers; naturalized in North America
biennial Eurasian white hairy thistle having pale purple flowers; naturalized in North America