Physical phenomenology of phyllotaxis

We propose an evolutionary mechanism of phyllotaxis, regular arrangement of leaves on a plant stem. It is shown that the phyllotactic pattern with the Fibonacci sequence has a selective advantage, for it involves the least number of phyllotactic transitions during plant growth.

► An evolutionary mechanism of phyllotaxis proposed.
► The Fibonacci phyllotaxis is naturally selected through phyllotactic transitions.
► Frequencies of occurrence of various phyllotactic sequences are assessed.
► Plain parastichy diagram based on a Stern-Brocot-type hierarchical tree.