grey poplar vs Populus canescens

grey poplar and Populus canescens both are nouns.

Word	Noun	Adjective	Verb	Adverb
grey poplar	Yes	No	No	No
Populus canescens	Yes	No	No	No

As nouns, grey poplar and Populus canescens are synonyms defined as:

grey poplar and Populus canescens: large rapidly growing poplar with faintly lobed dentate leaves grey on the lower surface; native to Europe but introduced and naturalized elsewhere

Other synonyms of grey poplar include gray poplar.

grey poplar (noun)	Populus canescens (noun)
large rapidly growing poplar with faintly lobed dentate leaves grey on the lower surface; native to Europe but introduced and naturalized elsewhere	large rapidly growing poplar with faintly lobed dentate leaves grey on the lower surface; native to Europe but introduced and naturalized elsewhere