black hickory vs Juglans nigra

black hickory and Juglans nigra both are nouns.

Word	Noun	Adjective	Verb	Adverb
black hickory	Yes	No	No	No
Juglans nigra	Yes	No	No	No

As nouns, black hickory and Juglans nigra are synonyms defined as:

black hickory and Juglans nigra: North American walnut tree with hard dark wood and edible nut

Other synonyms of black hickory include black walnut, black walnut tree.

black hickory (noun)	Juglans nigra (noun)
an American hickory tree having bitter nuts	North American walnut tree with hard dark wood and edible nut
smooth-barked North American hickory with 7 to 9 leaflets bearing a hard-shelled edible nut
North American walnut tree with hard dark wood and edible nut