Self-burial Mechanism of Erodium cicutarium and Its Potential Application for Subsurface Exploration

Erodium cicutarium L. plants disperse their seeds by a combination of two dispersal strategies: explosive dispersal, and self-burial dispersal. As the fruits dry, the stresses developed in the structure cause the sudden separation of the seeds that fly away from the plant. Then, once on the ground, the seeds respond to variations in the external humidity : their dispersal unit, is helical when dry and linear when wet. The day-night cycle of humidity results in a coiling and uncoiling motor action, that moves the seed across the surface and into the ground. The present study aims at getting a deeper insight into the self-burial strategy of Erodium cicutarium in order to implement this ability into mechanical structures that relying on changes in the external parameters (such as light, temperatures or humidity) can achieve passively the same goal.