Leaves – Flip Before a Storm
Q: I have a friend who was told that the leaves on trees flip over when it is going to rain, in order to better absorb the rainwater, and this is what gives trees their “silvery” tint before a storm. It sounded like an old wives tale to me and wondered if you could possibly answer her question.
A: I think your instinct is correct. The stomata (the breathing holes) on a leaf might open a bit wider before a storm as barometric pressure drops but the leaves do not flip over. Gusty winds might also flip the leaves and reveal lighter colored undersides. The lighter backside is common among trees. Aspen, beech, silver maple, euonymus and red maple all exhibit this phenomenon.