Western birch vs Western paper birch

Western birch and Western paper birch both are nouns.

Word	Noun	Adjective	Verb	Adverb
Western birch	Yes	No	No	No
Western paper birch	Yes	No	No	No

As nouns, Western birch and Western paper birch are synonyms defined as:

Western birch and Western paper birch: birch of western United States resembling the paper birch but having brownish bark

Other synonyms of Western birch include Betula fontinalis, mountain birch, swamp birch, water birch.

Western birch (noun)	Western paper birch (noun)
birch of western United States resembling the paper birch but having brownish bark	birch of western United States resembling the paper birch but having brownish bark