Fraxinus pennsylvanica vs downy ash

Fraxinus pennsylvanica and downy ash both are nouns.

Word	Noun	Adjective	Verb	Adverb
Fraxinus pennsylvanica	Yes	No	No	No
downy ash	Yes	No	No	No

As nouns, Fraxinus pennsylvanica and downy ash are synonyms defined as:

Fraxinus pennsylvanica and downy ash: smallish American tree with velvety branchlets and lower leaf surfaces

Other synonyms of Fraxinus pennsylvanica include red ash.

Fraxinus pennsylvanica (noun)	downy ash (noun)
smallish American tree with velvety branchlets and lower leaf surfaces	smallish American tree with velvety branchlets and lower leaf surfaces