Format: ORAL

Louis P. Ronse De Craene1, Julien B. Bachelier2, Florian Jabbour3

1 Royal Botanic Garden Edinburgh, Edinburgh, Scotland, UK 2 Biological Institute, Freie Universität Berlin, Berlin, Germany 3 Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum national d’Histoire naturelle, Paris, France

Morphology has always been the indispensable instrument for the exploration of biodiversity and studies of living organisms. Fundamental questions, such as the origin of flowers and their homology can only be properly answered from the perspective of ontogeny in a phylogenetic framework. Payer was the first to systematically create a comparative study of flowers in great detail, covering as many as 329 species, belonging in 130 families of flowering plants. His masterpiece, Trait dorganognie compare de la fleur, published in 1857 (1854 for the first edition), was advanced for his time and remains strongly relevant in its extraordinary accuracy and as a valuable counterpart of evo-devo studies. The floral developmental study of Payer has created the perfect conditions for the development of twentieth century schools of dynamic botany set against the more conservative typological approach. Comparative floral developmental studies allow for a better understanding of complex structures and are a key to understanding fundamental trends in floral evolution. As flowers are dynamic structures, often without clearcut boundaries between organs or tissues, an integration of ontogenetic and evolutionary approaches remains the cornerstone in understanding floral evolutionary change. Morphology has always been significant but becomes increasingly so, as the understanding of the floral phenotype is only relevant through integrative studies including pollination systems, gene expression and regulation, and development, demonstrating the importance of spatial constraints. The first part of the talk presents an overview of the significance of Payer as individual. The second part covers his legacy for modern morphological research. The third part explores a case study in the family Anacardiaceae, illustrating the importance of floral developmental evidence for floral studies.