XVI International Botanical Congess
The corkscrew shaped stems of twining vines have uniform curvature and torsion. In collaboration with M. Hubbard, A. Matista, and M. Holbrook, I have measured the forces exerted in situ by vines twining around a supporting pole,examined the lignifying fiber distribution as a function of developmental stage, and performed springback experiments to find the change in vine geometry after removal from the support. Empirical evidence supports the hypothesis that the twining habit is initiated with gradients in primary growth rates while structural stability is provided later in development, with secondary wall development and associated fiber contraction. Stem curvature is an essential component of the force balance that describes the interaction between the vine and its support.