rampion bellflower vs campanula

rampion bellflower and campanula both are nouns.

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

As nouns, campanula is a hypernym of rampion bellflower; that is, campanula is a word with a broader meaning than rampion bellflower:

rampion bellflower: bellflower of Europe and Asia and North Africa having bluish flowers and an edible tuberous root used with the leaves in salad
campanula: any of various plants of the genus Campanula having blue or white bell-shaped flowers

Other hypernyms of rampion bellflower include bellflower.

rampion bellflower (noun)	campanula (noun)
bellflower of Europe and Asia and North Africa having bluish flowers and an edible tuberous root used with the leaves in salad	any of various plants of the genus Campanula having blue or white bell-shaped flowers