The leaflets of black beans are 6 to 13 cm in length and 4 to 8.5 cm in width. They are ovate, broadly ovate or narrowly ovate in shape. Both sides are covered with yellow bristles.
Cowpea's leaflets are about 4cm in length and 3.5cm in width. The leaves are smaller and the shape is nearly diamond shaped. The petioles are shorter and grow about 5mm.
The seeds of black beans are elliptical or globular in shape, slightly flattened, about 6 to 12 mm in length and about 5 to 9 mm in diameter. Its appearance is glossy. On one side of it, there is a long oval navel in yellowish white. The seed coat is thin and crisp. The color is yellow green or light yellow. The pod is oblong lanceolate, 5 to 7 cm long and about 1 cm wide.
The seed shape of cowpea is quadrangular, the seed is smaller, the length is about 3 mm, the pod is linear, the length is 4.5 cm, the width is 5 mm.
