genus Agrostis vs family Poaceae

genus Agrostis and family Poaceae both are nouns.

Word	Noun	Adjective	Verb	Adverb
genus Agrostis	Yes	No	No	No
family Poaceae	Yes	No	No	No

genus Agrostis (noun)	family Poaceae (noun)
annual or perennial grasses cosmopolitan in Northern Hemisphere: bent grass (so named from `bent' meaning an area of unfenced grassland)	the grasses: chiefly herbaceous but some woody plants including cereals, bamboo, reeds, sugar cane