Section properties of palm petioles, part 2: The relationship of petiole histology with the torsional rigidity of the palm, Trachycarpus fortunei

Abstract

The Trachycarpus fortunei palm is a good example of a palm with a large leaf blade supported by a correspondingly large petiole. The interaction of the material and functional properties of the petiole was analysed using engineering and botanical methods with a view to understanding how the petiole functions from a structural standpoint. The histological aspects of the petiole were analysed from sections taken at regular intervals along the petiole axis, in order to determine the density and position of the vascular bundles. A modified torsion rig was then used to acquire torsion readings and calculate the rigidity modulus variation along the petiole. To supplement this, shape factor derived data from the Trachycarpus fortunei palm petiole were calculated and then compared with the empirical results and the differences analysed.