leather fern vs leatherleaf fern

leather fern and leatherleaf fern both are nouns.

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

As nouns, leather fern and leatherleaf fern are synonyms defined as:

leather fern and leatherleaf fern: widely distributed fern of tropical Southern Hemisphere having leathery pinnatifid fronds

Other synonyms of leather fern include Polystichum adiantiformis, Rumohra adiantiformis, ten-day fern.

leather fern (noun)	leatherleaf fern (noun)
widely distributed fern of tropical Southern Hemisphere having leathery pinnatifid fronds	widely distributed fern of tropical Southern Hemisphere having leathery pinnatifid fronds
stout tropical swamp fern (especially tropical America) having large fronds with golden yellow sporangia covering the undersides