Where do Southern pea types get their names?

The types are named after pod color, seed color, and seed shapes. Crowder peas look as if they have been crowded in the pod. Black eye peas have a ring around the hilum which looks like a black eye. Pink eye peas have a less dark ring than black eyes. Clay peas grow well on clay soils. Iron peas grow well on red soils. Purple hull and silver peas are named after the color of their pods. It is possible to have a pink eye, crowder, clay, silver pea.