Fraxinus ornus vs ash tree

Fraxinus ornus and ash tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
Fraxinus ornus	Yes	No	No	No
ash tree	Yes	No	No	No

As nouns, ash tree is a hypernym of Fraxinus ornus; that is, ash tree is a word with a broader meaning than Fraxinus ornus:

Fraxinus ornus: southern Mediterranean ash having fragrant white flowers in dense panicles and yielding manna
ash tree: any of various deciduous pinnate-leaved ornamental or timber trees of the genus Fraxinus

Other hypernyms of Fraxinus ornus include ash.

Fraxinus ornus (noun)	ash tree (noun)
southern Mediterranean ash having fragrant white flowers in dense panicles and yielding manna	any of various deciduous pinnate-leaved ornamental or timber trees of the genus Fraxinus