Adiantum vs fern genus

Adiantum and fern genus both are nouns.

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

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

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

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