birchen vs birch

birchen is not a noun while birch is a noun.

Word	Noun	Adjective	Verb	Adverb
birchen	No	Yes	No	No
birch	Yes	Yes	Yes	No

As adjectives, birchen and birch are synonyms defined as:

Other synonyms of birchen include birken.

birchen (noun)	birch (noun)
	a switch consisting of a twig or a bundle of twigs from a birch tree; used to hit people as punishment
	any betulaceous tree or shrub of the genus Betula having a thin peeling bark
	hard close-grained wood of any of various birch trees; used especially in furniture and interior finishes and plywood

birchen (adjective)	birch (adjective)
consisting of or made of wood of the birch tree	consisting of or made of wood of the birch tree

birchen (verb)	birch (verb)
	whip with a birch twig