Xylariaceae vs fungus family

Xylariaceae and fungus family both are nouns.

Word	Noun	Adjective	Verb	Adverb
Xylariaceae	Yes	No	No	No
fungus family	Yes	No	No	No

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

Xylariaceae (noun)	fungus family (noun)
family of fungi characterized by dark brown to black spores	includes lichen families