Western birch vs swamp birch

Western birch and swamp birch both are nouns.

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

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

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

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

Western birch (noun)	swamp 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