bellflower vs campanula

bellflower and campanula both are nouns.

Word	Noun	Adjective	Verb	Adverb
bellflower	Yes	No	No	No
campanula	Yes	No	No	No

As nouns, bellflower and campanula are synonyms defined as:

bellflower and campanula: any of various plants of the genus Campanula having blue or white bell-shaped flowers

bellflower (noun)	campanula (noun)
any of various plants of the genus Campanula having blue or white bell-shaped flowers	any of various plants of the genus Campanula having blue or white bell-shaped flowers