A finite deformation theory for the climbing habits and attachment of twining plants.

Abstract Twining plants, using their special attachment structure to cling to a support and grow upward to capture more sunshine without losing stability, have fascinated many scholars. A mechanics model to interpret this natural selection phenomenon based on the finite deformation theory is developed here. Results show the pitch angle of the twiner, the elongation in the stem and the radius ratio of the twiner to its support play an important role in the twining habit. To get more sunshine overhead, twiners tend to increase the initial pitch angle but to decrease the final twining angle to maintain their positions and stability. By taking into account of the tuning of the interfacial strength with the microstructure, the maximum values of the elongation and the support radius are determined, over which twiners will lose their ability to wind around. The proposed model and the results can not only clarify the mechanism of climbing habits and attachment, but also show the potential applications for the twining-mimic designs.