dogwood vs dogwood tree

dogwood and dogwood tree both are nouns.

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

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

dogwood and dogwood tree: a tree of shrub of the genus Cornus often having showy bracts resembling flowers

Other synonyms of dogwood include cornel.

dogwood (noun)	dogwood tree (noun)
a tree of shrub of the genus Cornus often having showy bracts resembling flowers	a tree of shrub of the genus Cornus often having showy bracts resembling flowers
hard tough wood of any dogwood of the genus Cornus; resembles boxwood