Dutch elm vs elm tree

Dutch elm and elm tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
Dutch elm	Yes	No	No	No
elm tree	Yes	No	No	No

As nouns, elm tree is a hypernym of Dutch elm; that is, elm tree is a word with a broader meaning than Dutch elm:

Dutch elm: any of various hybrid ornamental European shade trees ranging from dwarf to tall
elm tree: any of various trees of the genus Ulmus: important timber or shade trees

Other hypernyms of Dutch elm include elm.

Dutch elm (noun)	elm tree (noun)
any of various hybrid ornamental European shade trees ranging from dwarf to tall	any of various trees of the genus Ulmus: important timber or shade trees