family Brassicaceae vs genus Lepidium

family Brassicaceae and genus Lepidium both are nouns.

Word	Noun	Adjective	Verb	Adverb
family Brassicaceae	Yes	No	No	No
genus Lepidium	Yes	No	No	No

family Brassicaceae (noun)	genus Lepidium (noun)
a large family of plants with four-petaled flowers; includes mustards, cabbages, broccoli, turnips, cresses, and their many relatives	cosmopolitan genus of annual and biennial and perennial herbs: cress