Betula pubescens vs downy birch

Betula pubescens and downy birch both are nouns.

Word	Noun	Adjective	Verb	Adverb
Betula pubescens	Yes	No	No	No
downy birch	Yes	No	No	No

As nouns, Betula pubescens and downy birch are synonyms defined as:

Betula pubescens and downy birch: European birch with dull white to pale brown bark and somewhat drooping hairy branches

Other synonyms of Betula pubescens include white birch.

Betula pubescens (noun)	downy birch (noun)
European birch with dull white to pale brown bark and somewhat drooping hairy branches	European birch with dull white to pale brown bark and somewhat drooping hairy branches