black-eyed pea vs Vigna sinensis

black-eyed pea and Vigna sinensis both are nouns.

Word	Noun	Adjective	Verb	Adverb
black-eyed pea	Yes	No	No	No
Vigna sinensis	Yes	No	No	No

As nouns, black-eyed pea and Vigna sinensis are synonyms defined as:

black-eyed pea and Vigna sinensis: sprawling Old World annual cultivated especially in southern United States for food and forage and green manure

Other synonyms of black-eyed pea include cowpea, cowpea plant, Vigna unguiculata.

black-eyed pea (noun)	Vigna sinensis (noun)
eaten fresh as shell beans or dried	sprawling Old World annual cultivated especially in southern United States for food and forage and green manure
sprawling Old World annual cultivated especially in southern United States for food and forage and green manure
fruit or seed of the cowpea plant