"For example, some plants that track the sun with their leaves during the day are known to "reset" their leaves at night and move them back toward the east in anticipation of sunrise. " Some? Rather all. This is why it is wrong to turn plants around to get a "uniform" rounded appearance for Shows. I don't know the English expression for this but with woody plants it is most important to "respect the North" when transplanting or moving them to a different spot. Meaning, they should retain the same orientation with respect to the cardinal points.