Unexpectedly, this mechanism relies on the geometry of asymmetric secondary cell wall thickenings in the seed pod. These stiff cells’ walls are shaped like hinges, which can open. This flattens the cross-section of the seed pod wall, causing sudden mechanical failure of the structure and explosive coiling.

Why do pea pods explode?

As a pod dries, tensions are set up in the wall of the pod eventually causing it to split along two lines of weakness. As the two halves curl back, suddenly released like a tense spring, they flick out the seeds inside in an explosive manner.

What plants have exploding seed pods?

Jewelweed is an annual, meaning it lives only for one year and comes back from the seeds the next year. The seeds grow in pods, which expand in size, building up pressure – until they explode when touched. This is why they are also called touch-me-nots.