Betula populifolia vs grey birch

Betula populifolia and grey birch both are nouns.

Word	Noun	Adjective	Verb	Adverb
Betula populifolia	Yes	No	No	No
grey birch	Yes	No	No	No

As nouns, Betula populifolia and grey birch are synonyms defined as:

Betula populifolia and grey birch: medium-sized birch of eastern North America having white or pale grey bark and valueless wood; occurs often as a second-growth forest tree

Other synonyms of Betula populifolia include American gray birch, American grey birch, gray birch.

Betula populifolia (noun)	grey birch (noun)
medium-sized birch of eastern North America having white or pale grey bark and valueless wood; occurs often as a second-growth forest tree	medium-sized birch of eastern North America having white or pale grey bark and valueless wood; occurs often as a second-growth forest tree