This is the large bearded Iris, the most easily recognized. She comes in many colors and variations. Her upright pedals are called her standards. Her draping pedals are her falls.The purple, shown blue here has become variegated or stripped with white. Her true color is a sold purple. Variegation is the result of a virus. This particular virus has no damaging effects on the plant, save the alteration of some pigment cells.
I have seen this phenomenon in many different types of flowers, including the rose. The whole plant can variegate or only one part. This Iris is one of several in a large clump that have remained true to color. I have had a hybrid tea rose, "Out of the Blue," variegate in such a way as to leave only half the bush retaining its unadulterated and rich bluish magenta. I have also observed floribundas with one rose stripped among a cluster of roses seemingly immune to the virus.Variegation can last indefinitely or be gone in the next season. This tends to happen to darker color flowers in my experience. The pale peach and cream colored Iris is pristine. All in all, it is simply one of the Goddess’ little surprises.