grass family vs genus Buchloe

grass family and genus Buchloe both are nouns.

Word	Noun	Adjective	Verb	Adverb
grass family	Yes	No	No	No
genus Buchloe	Yes	No	No	No

grass family (noun)	genus Buchloe (noun)
the grasses: chiefly herbaceous but some woody plants including cereals, bamboo, reeds, sugar cane	buffalo grass