American dogwood vs red osier dogwood

American dogwood and red osier dogwood both are nouns.

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

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

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

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

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