Phyllotaxis as a dynamical system

One of the major puzzles in phyllotaxis is the much higher frequency of Fibonacci spirals compared to other spiral arrangements such as Lucas spirals. We show that spirals are a form of symmetry, in the same way that axial symmetry is a form of symmetry, which explains why they can be the consequence of many different microscopic phenomena. We apply dynamical systems theory to the main types of phyllotaxis. We show that only Fibonacci spirals should exist and that the other spiral modes (including Lucas) are the consequence of developmental errors, such as the dislocation of a pseudo-orthostichy.