bitter hickory vs bitter pignut

bitter hickory and bitter pignut both are nouns.

Word	Noun	Adjective	Verb	Adverb
bitter hickory	Yes	No	No	No
bitter pignut	Yes	No	No	No

As nouns, bitter hickory and bitter pignut are synonyms defined as:

bitter hickory and bitter pignut: hickory of the eastern United States having a leaves with 7 or 9 leaflets and thin-shelled very bitter nuts

Other synonyms of bitter hickory include bitternut, bitternut hickory, Carya cordiformis, swamp hickory.

bitter hickory (noun)	bitter pignut (noun)
hickory of the eastern United States having a leaves with 7 or 9 leaflets and thin-shelled very bitter nuts	hickory of the eastern United States having a leaves with 7 or 9 leaflets and thin-shelled very bitter nuts