1、 Different blades

The leaflets of black beans are 6 to 13 cm long and 4 to 8.5 cm wide. They are oval, broadly oval or narrowly oval in shape, and both sides are covered with yellow bristles

The length of the leaflet of cowpea is about 4cm and the width is about 3.5cm. The leaf blade is smaller, the shape is nearly rhombic, and the petiole is short and grows about 5mm

2、 Different seeds

The seeds of black beans are oval or spherical in shape, slightly flattened, about 6 to 12 mm in length and about 5 to 9 mm in diameter. The appearance is glossy. One side of it has a yellowish white long oval hilum. The seed coat is thin and brittle. The color is yellow green or light yellow. The pod is rectangular lanceolate, 5 to 7 cm long and 1 cm wide

The shape of cowpea seed is quadrangular, the seed is small, the length is about 3mm, and the pod is linear, 4.5cm long and 5mm wide