Initial transitions, order and disorder in phyllotactic patterns: the ontogeny of Helianthus annuus. A case study

摘要

The variability of the phyllotactic organization of Helianthus annuus L. Is investigated. Specimens exhibiting the various possible phyllotactic modes(Fibonacci spirals, Lucas spirals, bijugate spirals etc...) were selected. The transitions from the initial decussate growth to these organizations, were characterized and shown to correspond to only a few archetypes. The possible transients from a decussate mode were then investigated in the model of self organization introduced by Douady and Couder(1996a, b, c).