September elm vs elm

September elm and elm both are nouns.

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

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

September elm: autumn-flowering elm of southeastern United States
elm: any of various trees of the genus Ulmus: important timber or shade trees

Other hypernyms of September elm include elm tree.

September elm (noun)	elm (noun)
autumn-flowering elm of southeastern United States	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