I have a mature Butterfly under an overhang of my house. Those leaves that get sun have the normal green/white variegation, but many of the lower leaves (both lower on the same branch and on lower branches) have no green and are yellowish white? What is this lack of chlorophyll?
katsura, It would appear that your plants don't really like the position they are in currently (Re: Mildew), so if I were you I would transplant them in winter to a position that gets more sunlight and has better air circulation. Coloration in the leaves is related to pigment levels not necessarily the levels of chlorophyll because even red leaves contain chlorophyll. Good luck.
I love variegated leaves especially maples. What creates this variegation? When I ask experts they say many consider it a disease, and when I look at mosaic virus on some rose leaves, it does have a similarity. Can anyone steer me to literature on leave variegation please? Thank you.
Causes vary. There are one or two books out on variegated plants, these will probably come up (as well as web pages on the subject) if you search likely phrases such as "variegated plants" and "leaf variegation".
There are a few different causes for variegation... wikipedia has a good explanation of it here: http://en.wikipedia.org/wiki/Variegation
After much reading, I believe the answer to my initial inquiry re my Butterfly is variegation due to "etiolation".
Photomorphogenesis - what a topic. How do I "skate" by without getting into too much detail? Etiolation is a general term that has been applied to the change in leaf color as a result of lack of light. The thinking is that there is also a lack of chloroplasts so that the leaf will not be green as a result of having fewer chloroplasts combined with small to no amounts of ambient or direct light. Even leaves grown in total darkness can become green once they have been given some light. Think of seedlings we grew in the dark and remember how tall and rangy some of them became and were pale in color. What happened when we brought them into the light? Those that lived later turned green. We apply the term to refer to plants with elongated lateral stems with disfigured or poorly developed leaves due to lack of light by saying the plant has become etiolated. Once we give the same plant some light the stem elongation will shorten, the leaves will start to emerge with more normal sizes and shapes. Etiolation is not generally a permanent condition. If we look at these photos what we see are some pretty much all cream colored leaves but in the case of this plant where the leaves get the most sunlight there is a higher degree of variegation than the areas that receive less sunlight. The backside of this tree shows much more green in the variegated leaf coloration than the front of the tree does that faces directly into the morning sun. The concept of etiolation does not apply to this plant at all with its subsequent coloration in ample light. No, the coloring on your Butterfly is not due to etiolation. http://www.botanicalgarden.ubc.ca/forums/attachment.php?attachmentid=2404 http://www.botanicalgarden.ubc.ca/forums/attachment.php?attachmentid=2405 Jim
