Pea soup or split pea soup is soup made typically from dried peas, such as the split pea. It is, with variations, a part of the cuisine of many cultures. It is greyish-green or yellow in color depending on the regional variety of peas used; all are cultivars of Pisum sativum.Pea soup has been eaten since antiquity; it is mentioned in Aristophanes' The Birds, and according to one source "the Greeks and Romans were cultivating this legume about 500 to 400 BC.