Phyllotaxis triangular unit; phyllotactic transitions as the consequences of the apical wedge disclinations in a crystal-like pattern of the units

Abstract

The complexity of helical phyllotaxis expressed in diverse phyllotactic patterns and the phenomenon of phyllotactic transformations were investigated theoretically. Two categories of transformations were distinguished: continuous and discontinuous, the latter being interpreted as the consequences of wedge disclinations present at the shoot apex when the number of initials changes. Phyllotaxis triangular unit was described as the common element of all patterns of helical phyllotaxis. It is proposed that the unit plays the same role in a process of the formation of phyllotactic pattern as the crystal basic unit does in a process of crystal growth.