bitter floom vs Sabbatia stellaris

bitter floom and Sabbatia stellaris both are nouns.

Word	Noun	Adjective	Verb	Adverb
bitter floom	Yes	No	No	No
Sabbatia stellaris	Yes	No	No	No

As nouns, bitter floom and Sabbatia stellaris are synonyms defined as:

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

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

bitter floom (noun)	Sabbatia stellaris (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