cowpea vs Vigna sinensis

cowpea and Vigna sinensis both are nouns.

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

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

cowpea and Vigna sinensis: 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 unguiculata.

cowpea (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