Marsileaceae vs fern family

Marsileaceae and fern family both are nouns.

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

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

Marsileaceae: a family of heterosporous aquatic and semi-aquatic ferns, commonly known as the pepperwort family or the water-clover family (Marsileaceae)
fern family: families of ferns and fern allies

Marsileaceae (noun)	fern family (noun)
a family of heterosporous aquatic and semi-aquatic ferns, commonly known as the pepperwort family or the water-clover family (Marsileaceae)	families of ferns and fern allies