Sauerkirsche
"Prunus cerasus", a tetraploid with 2n=32 chromosomes, is thought to have originated as a natural hybrid between "Prunus avium" and "Prunus fruticosa" in the Iranian Plateau or Eastern Europe where the two species come into contact. "Prunus fruticosa" is believed to have provided its smaller size and sour tasting fruit. The hybrids then stabilized and interbred to form a new, distinct species.