Climbing plants -- Wrapping elastic plant stems around a cylindrical stake

TL;DR

This paper presents a simplified static model explaining why climbing plant stems tend to wrap around cylindrical stakes, emphasizing the roles of elasticity, stem fineness, and stake diameter in the climbing process.

Contribution

It introduces a static, energy-based model focusing on elasticity to explain plant stem wrapping behavior around cylindrical supports.

Findings

Stem elasticity dominates over gravity and turgor pressure in the model.

The diameter of the stake significantly influences the climbing pattern.

Fineness of the stem affects its ability to wrap around the stake.

Abstract

Since Charles Darwin's time, the study of climbing plants on a cylindrical stake has been the subject of numerous articles in plant biology. One of the main ideas for studying the coiling of an elastic plant stem is to consider the growth of the plant stem in terms of evolution over time. However, as this development takes place over a long time scale, the static study alone has not been studied independently. Our static approach requires us to take into account elasticity, turgor pressure and gravity forces in a first analysis. The aim of this article is to present a simplified model demonstrating why plant stems climb mainly on their circular helix-shaped stakes, with the diameter of the stake playing an important role in plant stem ascent, as does the fineness of the stem. To perform this calculation, for a given mass density, we consider the variational principle of minimum energy. For thin plant stems, we can see, in first approximation, that the effect of gravity and turgor pressure can be neglected with respect to the energy of elasticity, and that the bulk of the calculation concerns elasticity terms.