Morphologie et palynologie des Annonacées africaines: interrelations phylogéniques

Abstract

MORPHOLOGY AND PALYNOLOGY OF THE AFRICAN ANNONACEAE: PHYLOGENETICINTER-RELATIONS Taxonomy not only the practice of plant classification, but also a science of synthesis attempting to outline the possible stages followed by the evolution of a group. It attempts, therefore, to re-create and to explain the dynamics of the evolution of plants through the analysis of all their characters and of the relationships existing between them. Consequently, it can only benefit from the birth or development of all disciplines that analyse fresh aspects of plants or study them in time and space. For these reasons, palynology has developed considerably within taxonomy, revealing new morphological characters that permit a comparison with many fossil examples. In the family Annonaceae, of which the different classifications are admittedly artificial, pollen studies have shown that evolution is expressed in continuous morphological series along parallel lines. The established correlations with other morphological characters throw some light on certain phenomena of parallel evolution within the family, showing that the flower of the Annonaceae is in the process of reduction and the correlations contribute to a better knowledge of the affinities between generic taxa and their respective evolutionary levels.