Abstract
The plants growth forms have been studied many times but they still represent nowadays a fuzzy set, often modified because of the inconsistency and the heterogeneity of the methods used in their analysis. This lack of precision often leads to an inconsistency of the use of the growth forms as a trait in the studies of plants communities and their dynamics. We tried to remedy this situation by applying to some of them the architectural analysis initiated by Hallé and Oldeman, which has been relevant for the understanding of the tree growth form.This study aimed to 1) interpret these growth forms terms and their variability in architectural terms, 2) study architectural traits variation within roadsides plants communities during succession and in a mowing context. Our results show that 1) the architectural concepts and traits are also applicable to non-arborescent growth forms, 2) the expression of the reiteration is the main source of structural variation of growth forms at specific and intraspecific levels and 3) that traits values are changing during succession within the communities : Plants living at early successional stages got a simple architectural unit and reiterate at the base of the individual while plants living at late successional stages got complex architectural unit and can produce acrotonic reiteration. These results lead us to discuss the holistic value of the architectural analysis for growth forms characterization, of biological processes allowing for growth form variation and the interest of the use of architectural traits in plant communities studies.