California black walnut vs Juglans californica

California black walnut and Juglans californica both are nouns.

Word	Noun	Adjective	Verb	Adverb
California black walnut	Yes	No	No	No
Juglans californica	Yes	No	No	No

As nouns, California black walnut and Juglans californica are synonyms defined as:

California black walnut and Juglans californica: medium-sized tree with somewhat aromatic compound leaves and edible nuts

California black walnut (noun)	Juglans californica (noun)
medium-sized tree with somewhat aromatic compound leaves and edible nuts	medium-sized tree with somewhat aromatic compound leaves and edible nuts