grass family vs Avena

grass family and Avena both are nouns.

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

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