I would like to continue the topic of variegation (from the photo gallery discussion on Frosted Strawberry) and I am just throwing the following thoughts out here for discussion purposes. I have long wondered about the causes of variegation in maples and I believe that variegation can be caused in maples by a few of the factors below. Placing specific examples for each is very difficult. Natural Variegation: brought about through the consistant genetic expression of genes. This type leads to consistant patterns in leaves. Examples: sister ghost, ariadne, higasayama. Viral Variegation: brought about from viruses breaking down the formation of chlorophyll in parts of leaves, giving rise to various colors patterns in leaves from green to yellow to white. Examples: marakumo, A. c. pulverulentum Mutations: occuring naturally (spontaneously) and through forcing with chemicals (colchicine) in seeds which leads to the spontaneous expression of new genes (pigmention) in leaves. Examples: Chimeral Variegation: a natural process, this involves the switching on and off a genes at radomn continously as the plant grows. The mutations arise in the individual cell chloroplasts. Examples: asahi zuru, toyama nishiki Side note: Plants have a hard time making their way into the US from Japan and other parts of the world for fear of bringing the Mosaic Maple virus here. It is most likely here already and I wonder how virulent of a disease it is (I have rubbed numerous variegated leaves onto healthy non-variegated leaves to no avail).