Mature seeds are oblate or semi-oval, 2 ~ 4 mm long and 1.5 ~ 3 mm wide, with black surface, protruding on one side, thick and thin reticular wrinkles, and slightly concave on the other side without obvious wrinkles. The top is blunt, the base is slightly sharp, and a little protruding navel can be seen. Hard, peculiar, slightly pungent. The color is black, full of seeds and free of impurities.