cowpea plant vs Vigna sinensis

cowpea plant and Vigna sinensis both are nouns.

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

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

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

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

cowpea plant (noun)	Vigna sinensis (noun)
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