grass family vs genus Avena

grass family and genus Avena both are nouns.

Word	Noun	Adjective	Verb	Adverb
grass family	Yes	No	No	No
genus Avena	Yes	No	No	No

grass family (noun)	genus Avena (noun)
the grasses: chiefly herbaceous but some woody plants including cereals, bamboo, reeds, sugar cane	oats