shellbark hickory vs hickory

shellbark hickory and hickory both are nouns.

Word	Noun	Adjective	Verb	Adverb
shellbark hickory	Yes	No	No	No
hickory	Yes	No	No	No

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

shellbark hickory: North American hickory having loose grey shaggy bark and edible nuts
hickory: American hardwood tree bearing edible nuts

Other hypernyms of shellbark hickory include hickory tree.

shellbark hickory (noun)	hickory (noun)
North American hickory having loose grey shaggy bark and edible nuts	American hardwood tree bearing edible nuts
	valuable tough heavy hardwood from various hickory trees