genus Christella vs fern genus

genus Christella and fern genus both are nouns.

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

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

genus Christella: medium to large terrestrial ferns of tropical forests of Old World to Americas
fern genus: genera of ferns and fern allies

genus Christella (noun)	fern genus (noun)
medium to large terrestrial ferns of tropical forests of Old World to Americas	genera of ferns and fern allies