New York fern vs fern

New York fern and fern both are nouns.

Word	Noun	Adjective	Verb	Adverb
New York fern	Yes	No	No	No
fern	Yes	No	No	No

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

New York fern: slender shield fern of moist woods of eastern North America; sometimes placed in genus Dryopteris
fern: any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores

New York fern (noun)	fern (noun)
slender shield fern of moist woods of eastern North America; sometimes placed in genus Dryopteris	any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores