cowpea vs Vigna unguiculata

cowpea and Vigna unguiculata both are nouns.

Word	Noun	Adjective	Verb	Adverb
cowpea	Yes	No	No	No
Vigna unguiculata	Yes	No	No	No

As nouns, cowpea and Vigna unguiculata are synonyms defined as:

cowpea and Vigna unguiculata: sprawling Old World annual cultivated especially in southern United States for food and forage and green manure

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

cowpea (noun)	Vigna unguiculata (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