Fig 16. Drying coiling catapult mechanism in the geranium Erodium cicutarium.

(A) Fruit consisting of five interconnected pericarps with long awns. (B) Dehydration of the awns creates tension in the awns, as the preferred dry shape of the awns is helical, resulting in dehiscence. (C) When a critical stress is reached, complete dehiscence of the connection between the awns discharges the seeds. (D) A discharged dry seed with awn. Drawings based on a photograph in [82]. Scale bar 20 mm.