Natural coil springs: Biomechanics and morphology of the coiled tendrils of the climbing passion flower Passiflora discophora.

Tendrils of climbing plants possess a striking spring-like structure characterized by a minimum of two helices of opposite handedness connected by a perversion. By performing tensile experiments and morphological measurements on tendrils of the climbing passion flower Passiflora discophora, we show that these tendril springs act as coil springs within the plant's attachment system and resemble technical coil springs. However, tendril springs have a low spring index and a high pitch angle compared with typical metal coil springs resulting in a more complex loading situation in the plant tendrils.

Leaf unfolding and lamina biomechanics inand.

In nature, leaves and their laminae vary in shape, appearance and unfolding behaviour. We investigated peltate leaves of two model species with peltate leaves and highly different morphology (and) and two distinct unfolding patterns via time-lapse recordings: we observed successive unfolding of leaf halves inand simultaneous unfolding inFurthermore, we gathered relevant morphological and biomechanical data in juvenile (unfolding) and adult (fully unfolded) leaves of both species by measuring the thickness and the tensile modulus of both lamina and veins as a measure of their stiffness. In, lamina and veins stiffen after unfolding, which may facilitate unfolding in the less stiff juvenile lamina.

Jumping with adhesion: landing surface incline alters impact force and body kinematics in crested geckos.

Arboreal habitats are characterized by a complex three-dimensional array of branches that vary in numerous characteristics, including incline, compliance, roughness, and diameter. Gaps must often be crossed, and this is frequently accomplished by leaping. Geckos bearing an adhesive system often jump in arboreal habitats, although few studies have examined their jumping biomechanics.