Pea soup is soup made, typically, from dried peas. 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. During that era, vendors in the streets of Athens were selling hot pea soup."