A Passionate Free Climber: Structural Development and Functional Morphology of the Adhesive Tendrils in Passiflora discophora

Abstract

Premise of research. Passiflora discophora is exceptional among passion flowers for its climbing strategy, using branched tendrils with terminal adhesive pads instead of coiling tendrils as typical within this family. This article investigates the structural development and morphology of these adhesive pads and aims to understand the underlying structure-function relationship of the attachment process. Based on our results, we discuss possible mechanical consequences of the tendril structure and compare our findings with similar attachment systems in unrelated species in order to identify general strategies of this mode of attachment.Methodology. We investigated the temporal development of the attachment process, including detailed studies of the morphology and anatomy of the adhesive pads, using LM with different staining procedures and SEM.Pivotal results. Young tendrils establish initial contact with a supporting substrate by interlocking with their hook-shaped tips. Touch stimuli induce the tips to de...