dagger fern vs fern

dagger fern and fern both are nouns.

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

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

dagger fern: North American evergreen fern having pinnate leaves and dense clusters of lance-shaped fronds
fern: any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores

dagger fern (noun)	fern (noun)
North American evergreen fern having pinnate leaves and dense clusters of lance-shaped fronds	any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores