ash vs ash tree

ash and ash tree both are nouns.

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

As nouns, ash and ash tree are synonyms defined as:

ash and ash tree: any of various deciduous pinnate-leaved ornamental or timber trees of the genus Fraxinus

ash (noun)	ash tree (noun)
any of various deciduous pinnate-leaved ornamental or timber trees of the genus Fraxinus	any of various deciduous pinnate-leaved ornamental or timber trees of the genus Fraxinus
strong elastic wood of any of various ash trees; used for furniture and tool handles and sporting goods such as baseball bats
the residue that remains when something is burned

ash (verb)	ash tree (verb)
convert into ashes