davallia vs fern

davallia and fern both are nouns.

Word	Noun	Adjective	Verb	Adverb
davallia	Yes	No	No	No
fern	Yes	No	No	No

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

davallia: any fern of the genus Davallia; having scaly creeping rhizomes
fern: any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores

davallia (noun)	fern (noun)
any fern of the genus Davallia; having scaly creeping rhizomes	any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores