01203nas a2200133   4500008004100000245007700041210006900118490000800187520076200195100002500957700002200982700002201004856004301026       2021                        eng d00aNutations in growing plant shoots as a morphoelastic flutter instability0 aNutations in growing plant shoots as a morphoelastic flutter ins0 v3793 a<p>Growing plant shoots exhibit spontaneous oscillations that Darwin observed, and termed "circumnutations". Recently, they have received renewed attention for the design and optimal actuation of bioinspired robotic devices. We discuss a possible interpretation of these spontaneous oscillations as a Hopf-type bifurcation in a growing morphoelastic rod. Using a three-dimensional model and numerical simulations, we analyse the salient features of this flutter-like phenomenon (e.g. the characteristic period of the oscillations) and their dependence on the model details (in particular, the impact of choosing different growth models) finding that, overall, these features are robust with respect to changes in the details of the growth model adopted.</p>1 aAgostinelli, Daniele1 aNoselli, Giovanni1 aDeSimone, Antonio  uhttps://doi.org/10.1098/rsta.2020.0116