redbrush vs dogwood tree

redbrush and dogwood tree both are nouns.

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

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

redbrush: common North American shrub with reddish purple twigs and white flowers
dogwood tree: a tree of shrub of the genus Cornus often having showy bracts resembling flowers

Other hypernyms of redbrush include cornel, dogwood.

redbrush (noun)	dogwood tree (noun)
common North American shrub with reddish purple twigs and white flowers	a tree of shrub of the genus Cornus often having showy bracts resembling flowers