buttercup family vs family Ranunculaceae

buttercup family and family Ranunculaceae both are nouns.

Word	Noun	Adjective	Verb	Adverb
buttercup family	Yes	No	No	No
family Ranunculaceae	Yes	No	No	No

As nouns, buttercup family and family Ranunculaceae are synonyms defined as:

Other synonyms of buttercup family include crowfoot family, Ranunculaceae.

buttercup family (noun)	family Ranunculaceae (noun)
a family of Ranunculaceae	a family of Ranunculaceae