# Biomechanical tactics of chiral growth in emergent aquatic macrophytes

## TL;DR

This paper explores how aquatic plants use twisted shapes to survive better in their environment.

## Contribution

The study reveals how chiral growth in aquatic plants enhances their structural resilience through biomechanical analysis and modeling.

## Key findings

- Twisting chirality in aquatic plants improves survivability against internal and external loads.
- Theoretical models align with experimental data on chiral configurations in plant structures.
- Different chiral growth tactics correlate with optimized biomechanical functions in plants.

## Abstract

Through natural selection, many plant organs have evolved optimal morphologies at different length scales. However, the biomechanical strategies for different plant species to optimize their organ structures remain unclear. Here, we investigate several species of aquatic macrophytes living in the same natural environment but adopting distinctly different twisting chiral morphologies. To reveal the principle of chiral growth in these plants, we performed systematic observations and measurements of morphologies, multiscale structures, and mechanical properties of their slender emergent stalks or leaves. Theoretical modeling of pre-twisted beams in bending and buckling indicates that the different growth tactics of the plants can be strongly correlated with their biomechanical functions. It is shown that the twisting chirality of aquatic macrophytes can significantly improve their survivability against failure under both internal and external loads. The theoretical predictions for different chiral configurations are in excellent agreement with experimental measurements.