black-eyed pea vs cowpea

An African leguminous plant, of the species Vigna unguiculata, widely cultivated as food and forage, specifically Vigna unguiculata subsp. unguiculata. 

The edible seed of these plants. 

Any pale bean with a black spot. 

Any of the plants in the species Vigna unguiculata, including the black-eyed pea.