European field elm vs elm tree

European field elm and elm tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
European field elm	Yes	No	No	No
elm tree	Yes	No	No	No

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

European field elm: European elm with lustrous smooth leaves used as an ornamental
elm tree: any of various trees of the genus Ulmus: important timber or shade trees

Other hypernyms of European field elm include elm.

European field elm (noun)	elm tree (noun)
European elm with lustrous smooth leaves used as an ornamental	any of various trees of the genus Ulmus: important timber or shade trees