red osier dogwood vs American dogwood

red osier dogwood and American dogwood both are nouns.

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

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

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

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

red osier dogwood (noun)	American dogwood (noun)
common North American shrub with reddish purple twigs and white flowers	common North American shrub with reddish purple twigs and white flowers