family Brassicaceae vs genus Descurainia

family Brassicaceae and genus Descurainia both are nouns.

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

family Brassicaceae (noun)	genus Descurainia (noun)
a large family of plants with four-petaled flowers; includes mustards, cabbages, broccoli, turnips, cresses, and their many relatives	includes annual or biennial herbs of America and Europe very similar to and often included among those of genera Sisymbrium or Hugueninia; not recognized in some classification systems