How Pine Cones Know When Rain is Coming
These little things are packed with predictive power.
Howdy! It’s Joey, back with more Fun Fact Friyay. Today’s fact might have you walking on pin(e)s and needles.
Pine cones can “predict” when it’s going to rain.
In the movie “Mean Girls,” the character of Karen Smith (played excellently by Amanda Seyfried) has a “fifth sense”: she can tell when it’s going to rain.
“It’s like I have ESPN, or something,” she claims.
Of course, her psychic abilities are more “in the moment.” She can tell you when it’s currently raining.
Still not a bad talent, considering some of those quick showers that douse areas in California and Florida and end before you’ve had a chance to say, “We really needed it.”
Karen’s predictive skills have nothing on pine trees, though. Despite having no living cells, muscles, or nerves, pine trees (and more specifically, pine cones) can indicate when rain is around the corner.
Pine cones release their seeds when weather conditions are optimal, and wet weather ain’t that time. The seeds require dry air with nice gusts of winds to spread them across the land.
When the environment is dry, pine cones on the ground appear more open, with their scales moving down, similar to the motion of uncurling a fist. When the air is humid, which often indicates rain is on the way, the pine cone’s scales clamp up to seal the cone into a tightly-wound ball.
Pine cone scales have multiple layers. The outermost layer consists of stretchable cells, while the inner layer is full of stiff fibers.
In dry weather, when the cone is open, the cone’s stiff fibers and stretchable cells are the same length and sit parallel to each other.
When there’s more moisture hanging around, the stiff fibers maintain the same length. However, the stretchable cells absorb water drops, causing them to expand and sending the scales curling upwards toward the rest of the cone.
This process usually occurs when humidity levels hit around 20 percent. The water moves toward the cone’s central stalk and then flows toward those interior parts of the scales. As the water fills up the empty spaces between cells, it causes the cone to curl until conditions become drier once again.
Some folks also believe oak and ash trees can let you know what kind of weather is on the way, though there’s not nearly as much evidence of that. They’ll just have to keep pining for pine cones.
Now, let’s dance!