American dogwood vs red dogwood

American dogwood and red dogwood both are nouns.

Word	Noun	Adjective	Verb	Adverb
American dogwood	Yes	No	No	No
red dogwood	Yes	No	No	No

As nouns, American dogwood and red dogwood are synonyms defined as:

American dogwood and red dogwood: common North American shrub with reddish purple twigs and white flowers

Other synonyms of American dogwood include Cornus stolonifera, red osier, red osier dogwood, redbrush.

American dogwood (noun)	red dogwood (noun)
common North American shrub with reddish purple twigs and white flowers	common North American shrub with reddish purple twigs and white flowers
	European deciduous shrub turning red in autumn having dull white flowers