black-eyed pea vs string bean

black-eyed pea

noun

  • Any pale bean with a black spot. 

  • 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. 

string bean

noun

  • A common bean (Phaseolus vulgaris) 

  • A hyacinth bean (Lablab purpureus) 

  • Any long, slender green bean. 

  • A tall and thin person. 

  • An immature runner bean (Phaseolus coccineus) 

  • A yardlong bean (Vigna unguiculata subsp. sesquipedalis) 

How often have the words black-eyed pea and string bean occurred in a corpus of books? (source: Google Ngram Viewer )