nutmeg hickory vs hickory tree

nutmeg hickory and hickory tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
nutmeg hickory	Yes	No	No	No
hickory tree	Yes	No	No	No

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

nutmeg hickory: hickory of southern United States and Mexico having hard nutmeg-shaped nuts
hickory tree: American hardwood tree bearing edible nuts

Other hypernyms of nutmeg hickory include hickory.

nutmeg hickory (noun)	hickory tree (noun)
hickory of southern United States and Mexico having hard nutmeg-shaped nuts	American hardwood tree bearing edible nuts