genus Adiantum vs fern genus

genus Adiantum and fern genus both are nouns.

Word	Noun	Adjective	Verb	Adverb
genus Adiantum	Yes	No	No	No
fern genus	Yes	No	No	No

As nouns, fern genus is a hypernym of genus Adiantum; that is, fern genus is a word with a broader meaning than genus Adiantum:

genus Adiantum: cosmopolitan genus of ferns: maidenhair ferns; in some classification systems placed in family Polypodiaceae or Adiantaceae
fern genus: genera of ferns and fern allies

genus Adiantum (noun)	fern genus (noun)
cosmopolitan genus of ferns: maidenhair ferns; in some classification systems placed in family Polypodiaceae or Adiantaceae	genera of ferns and fern allies