Poaceae vs genus Stenotaphrum

Poaceae and genus Stenotaphrum both are nouns.

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

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