Poaceae vs genus Panicum

Poaceae and genus Panicum both are nouns.

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

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