THE CONSTRAINTS OF GLOBAL FORM ON PHYLLOTACTIC ORGANIZATION - THE CASE OF SYMPLOCARPUS (ARACEAE)

The present paper describes a formal analysis of the constraints impos ed by a change of global form on the phyllotactic organization in the inflorescence of Symplocarpus. By combining a dynamic model of phyllot axis with a general model of allometric growth, we show that as the le ngth-to-width ratio of the inflorescence increases, then the number of parastichies decreases while the plastochrone ratio increases. Subseq uent observations prove that these theoretical conclusions emerging fr om the analysis of the global form of Symplocarpus are exact. Our anal ysis offers experimentalists the possibility of verifying the existenc e of particular allometric relationships in the different phases of de velopment of Symplocarpus and related species. (C) 1996 Academic Press Limited