black hickory vs black walnut

black hickory and black walnut both are nouns.

Word	Noun	Adjective	Verb	Adverb
black hickory	Yes	No	No	No
black walnut	Yes	No	No	No

As nouns, black hickory and black walnut are synonyms defined as:

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

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

black hickory (noun)	black walnut (noun)
an American hickory tree having bitter nuts	American walnut having a very hard and thick woody shell
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
North American walnut tree with hard dark wood and edible nut