Arizona ash vs ash tree

Arizona ash and ash tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
Arizona ash	Yes	No	No	No
ash tree	Yes	No	No	No

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

Arizona ash: small shrubby ash of southwestern United States and northwestern Mexico
ash tree: any of various deciduous pinnate-leaved ornamental or timber trees of the genus Fraxinus

Other hypernyms of Arizona ash include ash.

Arizona ash (noun)	ash tree (noun)
small shrubby ash of southwestern United States and northwestern Mexico	any of various deciduous pinnate-leaved ornamental or timber trees of the genus Fraxinus