Siberian elm vs elm

Siberian elm and elm both are nouns.

Word	Noun	Adjective	Verb	Adverb
Siberian elm	Yes	No	No	No
elm	Yes	No	No	No

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

Siberian elm: fast-growing shrubby Asian tree naturalized in United States for shelter or ornament
elm: any of various trees of the genus Ulmus: important timber or shade trees

Other hypernyms of Siberian elm include elm tree.

Siberian elm (noun)	elm (noun)
fast-growing shrubby Asian tree naturalized in United States for shelter or ornament	any of various trees of the genus Ulmus: important timber or shade trees
	hard tough wood of an elm tree; used for e.g. implements and furniture