Beans are called black kidney beans, which are essentially vegetable beans, not real black beans. The cotyledon part of black beans (watercress) has only two colors, yellow and black. The watercress in the photo is white. Bean navel (white dot on the side of epidermis), the bean navel of black kidney bean is a white dot, and the bean navel of black bean is a white line in the middle, and the periphery is black; Second, look at cotyledons. Cotyledons of black kidney beans are white, and cotyledons of black beans are yellow and green. Under normal circumstances, the water soaked in black beans is purplish red, and it is purplish red or reddish after dilution; The water soaked by black kidney beans is dark in color and generally black.