downy ash vs Fraxinus pennsylvanica

downy ash and Fraxinus pennsylvanica both are nouns.

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

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

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

Other synonyms of downy ash include red ash.

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