family Poaceae vs graminaceous plant

family Poaceae and graminaceous plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
family Poaceae	Yes	No	No	No
graminaceous plant	Yes	No	No	No

family Poaceae (noun)	graminaceous plant (noun)
the grasses: chiefly herbaceous but some woody plants including cereals, bamboo, reeds, sugar cane	cosmopolitan herbaceous or woody plants with hollow jointed stems and long narrow leaves