Hymenophyllaceae vs fern family

Hymenophyllaceae and fern family both are nouns.

Word	Noun	Adjective	Verb	Adverb
Hymenophyllaceae	Yes	No	No	No
fern family	Yes	No	No	No

As nouns, fern family is a hypernym of Hymenophyllaceae; that is, fern family is a word with a broader meaning than Hymenophyllaceae:

Hymenophyllaceae (noun)	fern family (noun)
terrestrial (hygrophytic) or epiphytic ferns: filmy ferns	families of ferns and fern allies