Another Freak Calla
This oddity was observed on one of Mr. Burbank's yellow Calla plants. It will be noted that the true leaf shows a tendency to turn yellow, while the spathe has the green markings of the leaf on its back. This is but one of innumerable freaks or sports such as are encountered in large quantity production of plants; and it is from these oddities, often, that new ideas of old and useful heredity within the plant are made evident to the plant improver.
This image is from: Luther Burbank: his methods and discoveries and their practical application. Volume 2 Chapter 3