Also, variegated trees can produce non-variegated branches which can make the whole tree look like it has two different sets of leaves: one green, one gold/variegated or whatever. There's a type of sycamore this happens with I believe, and it also occurs with some ornamental shrubs. A grafted tree (such as a fruit tree with one variety grafted on to a different rootstock) can sometimes produce shoots from the rootstock below the graft and these may be far more vigorous than the "new" tree. It happens, too, with my Corkscrew Hazel, where strong, straight shoots grow from below the graft and have to be regularly removed to prevent them taking over.
Whoops, we seem to have moved even further away from holey acorns and insects....
