leather fern vs fern

leather fern and fern both are nouns.

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

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

leather fern: widely distributed fern of tropical Southern Hemisphere having leathery pinnatifid fronds
fern: any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores

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

leather fern: stout tropical swamp fern (especially tropical America) having large fronds with golden yellow sporangia covering the undersides
fern: any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores

leather fern (noun)	fern (noun)
widely distributed fern of tropical Southern Hemisphere having leathery pinnatifid fronds	any of numerous flowerless and seedless vascular plants having true roots from a rhizome and fronds that uncurl upward; reproduce by spores
stout tropical swamp fern (especially tropical America) having large fronds with golden yellow sporangia covering the undersides