Poaceae vs genus Lolium

Poaceae and genus Lolium both are nouns.

Word	Noun	Adjective	Verb	Adverb
Poaceae	Yes	No	No	No
genus Lolium	Yes	No	No	No

Poaceae (noun)	genus Lolium (noun)
the grasses: chiefly herbaceous but some woody plants including cereals, bamboo, reeds, sugar cane	darnel; ryegrass