Fraxinus excelsior vs European ash

Fraxinus excelsior and European ash both are nouns.

Word	Noun	Adjective	Verb	Adverb
Fraxinus excelsior	Yes	No	No	No
European ash	Yes	No	No	No

As nouns, Fraxinus excelsior and European ash are synonyms defined as:

Fraxinus excelsior and European ash: tall ash of Europe to the Caucasus having leaves shiny dark-green above and pale downy beneath

Other synonyms of Fraxinus excelsior include common European ash.

Fraxinus excelsior (noun)	European ash (noun)
tall ash of Europe to the Caucasus having leaves shiny dark-green above and pale downy beneath	tall ash of Europe to the Caucasus having leaves shiny dark-green above and pale downy beneath