Did you know that some flowers can tell when it's going to rain?
William Smith of Wake Forest University and Michael Bynum of the University of Wyoming did experiments on Gentiana algid, aka gentians! They found that a type of gentian that grows in the mountains of North America is able to sense the cold air that precedes a rain storm. These gentians are able to close up in order to shelter their reproductive parts from the rain, and prevent their pollen from getting washed away.
Smith and Bynum clocked the closing gentians at ten percent per minute. It's not a blinding speed, but it's enough to save you from a soaking. Afterward, the little fellows open up again and go back to catching sunbeams.
"Shut up! A Thunderstorm's On the Way" (Science News)