Arrhenatherum vs grass family

Arrhenatherum and grass family both are nouns.

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

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