filago vs herba impia

filago and herba impia both are nouns.

Word	Noun	Adjective	Verb	Adverb
filago	Yes	No	No	No
herba impia	Yes	No	No	No

As nouns, herba impia is a hyponym of filago; that is, herba impia is a word with a more specific, narrower meaning than filago:

filago: any plant of the genus Filago having capitate clusters of small woolly flower heads
herba impia: (literally an undutiful herb) a variety of cotton rose

Other hyponyms of filago include Filago germanica.

filago (noun)	herba impia (noun)
any plant of the genus Filago having capitate clusters of small woolly flower heads	(literally an undutiful herb) a variety of cotton rose