bitter floom vs American centaury

bitter floom and American centaury both are nouns.

Word	Noun	Adjective	Verb	Adverb
bitter floom	Yes	No	No	No
American centaury	Yes	No	No	No

As nouns, bitter floom and American centaury are synonyms defined as:

bitter floom and American centaury: any of several pink-flowered marsh plant of the eastern United States resembling a true centaury

Other synonyms of bitter floom include marsh pink, rose pink, Sabbatia Angularis, Sabbatia stellaris.

bitter floom (noun)	American centaury (noun)
any of several pink-flowered marsh plant of the eastern United States resembling a true centaury	any of several pink-flowered marsh plant of the eastern United States resembling a true centaury