What structures does a kidney bean have or look like?

A kidney bean is named for its distinct shape, resembling a human kidney, with a smooth, oval form that is slightly curved. Its outer skin is typically a deep red or dark brown color, with a shiny surface. Inside, the bean contains a starchy endosperm surrounded by a thin seed coat, and it has a prominent hilum, or seed scar, which is where it was attached to the pod. The overall appearance is plump and firm, making it easily recognizable among other legumes.