genus Pteris vs fern genus

genus Pteris and fern genus both are nouns.

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

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

genus Pteris: large genus of terrestrial ferns of tropics and subtropics; sometimes placed in family Polypodiaceae
fern genus: genera of ferns and fern allies

genus Pteris (noun)	fern genus (noun)
large genus of terrestrial ferns of tropics and subtropics; sometimes placed in family Polypodiaceae	genera of ferns and fern allies