birch vs genus Betula

birch and genus Betula both are nouns.

Word	Noun	Adjective	Verb	Adverb
birch	Yes	Yes	Yes	No
genus Betula	Yes	No	No	No

birch (noun)	genus Betula (noun)
a switch consisting of a twig or a bundle of twigs from a birch tree; used to hit people as punishment	a genus of trees of the family Betulaceae (such as birches)
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

birch (adjective)	genus Betula (adjective)
consisting of or made of wood of the birch tree

birch (verb)	genus Betula (verb)
whip with a birch twig