Arrhenatherum vs family Graminaceae

Arrhenatherum and family Graminaceae both are nouns.

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

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