Poaceae vs genus Glyceria

Poaceae and genus Glyceria both are nouns.

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

Poaceae (noun)	genus Glyceria (noun)
the grasses: chiefly herbaceous but some woody plants including cereals, bamboo, reeds, sugar cane	manna grass