Ulmus laevis vs elm tree

Ulmus laevis and elm tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
Ulmus laevis	Yes	No	No	No
elm tree	Yes	No	No	No

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

Ulmus laevis: Eurasian elm closely resembling the American elm; thrives in a moist environment
elm tree: any of various trees of the genus Ulmus: important timber or shade trees

Other hypernyms of Ulmus laevis include elm.

Ulmus laevis (noun)	elm tree (noun)
Eurasian elm closely resembling the American elm; thrives in a moist environment	any of various trees of the genus Ulmus: important timber or shade trees