white poplar vs Populus alba

white poplar and Populus alba both are nouns.

Word	Noun	Adjective	Verb	Adverb
white poplar	Yes	No	No	No
Populus alba	Yes	No	No	No

As nouns, white poplar and Populus alba are synonyms defined as:

white poplar and Populus alba: a poplar that is widely cultivated in the United States; has white bark and leaves with whitish undersurfaces

Other synonyms of white poplar include abele, aspen poplar, silver-leaved poplar, white aspen.

white poplar (noun)	Populus alba (noun)
a poplar that is widely cultivated in the United States; has white bark and leaves with whitish undersurfaces	a poplar that is widely cultivated in the United States; has white bark and leaves with whitish undersurfaces
light easily worked wood of a tulip tree; used for furniture and veneer