dwarf cornel vs dogwood tree

dwarf cornel and dogwood tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
dwarf cornel	Yes	No	No	No
dogwood tree	Yes	No	No	No

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

dwarf cornel: creeping perennial herb distinguished by red berries and clustered leaf whorls at the tips of shoots; Greenland to Alaska
dogwood tree: a tree of shrub of the genus Cornus often having showy bracts resembling flowers

Other hypernyms of dwarf cornel include cornel, dogwood.

dwarf cornel (noun)	dogwood tree (noun)
creeping perennial herb distinguished by red berries and clustered leaf whorls at the tips of shoots; Greenland to Alaska	a tree of shrub of the genus Cornus often having showy bracts resembling flowers