black hickory vs brown hickory

black hickory and brown hickory both are nouns.

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

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

black hickory and brown hickory: an American hickory tree having bitter nuts

Other synonyms of black hickory include Carya glabra, pignut, pignut hickory.

black hickory (noun)	brown hickory (noun)
an American hickory tree having bitter nuts	an American hickory tree having bitter nuts
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