blood-twig vs dogwood tree

blood-twig and dogwood tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
blood-twig	Yes	No	No	No
dogwood tree	Yes	No	No	No

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

blood-twig: European deciduous shrub turning red in autumn having dull white flowers
dogwood tree: a tree of shrub of the genus Cornus often having showy bracts resembling flowers

Other hypernyms of blood-twig include cornel, dogwood.

blood-twig (noun)	dogwood tree (noun)
European deciduous shrub turning red in autumn having dull white flowers	a tree of shrub of the genus Cornus often having showy bracts resembling flowers