family Cactaceae vs cactus family

family Cactaceae and cactus family both are nouns.

Word	Noun	Adjective	Verb	Adverb
family Cactaceae	Yes	No	No	No
cactus family	Yes	No	No	No

As nouns, family Cactaceae and cactus family are synonyms defined as:

Other synonyms of family Cactaceae include Cactaceae.

family Cactaceae (noun)	cactus family (noun)
constituting the order Opuntiales	constituting the order Opuntiales