title: How (much) do flowers vary? Unbalanced disparity among flower functional modules and a mosaic pattern of morphospace occupation in the order Ericales.
abstract: The staggering diversity of angiosperms and their flowers has fascinated scientists for centuries. However, the quantitative distribution of floral morphological diversity (disparity) among lineages and the relative contribution of functional modules (perianth, androecium and gynoecium) to total floral disparity have rarely been addressed. Focusing on a major angiosperm order (Ericales), we compiled a dataset of 37 floral traits scored for 381 extant species and nine fossils. We conducted morphospace analyses to explore phylogenetic, temporal and functional patterns of disparity. We found that the floral morphospace is organized as a continuous cloud in which most clades occupy distinct regions in a mosaic pattern, that disparity increases with clade size rather than age, and that fossils fall in a narrow portion of the space. Surprisingly, our study also revealed that among functional modules, it is the androecium that contributes most to total floral disparity in Ericales. We discuss our findings in the light of clade history, selective regimes as well as developmental and functional constraints acting on the evolution of the flower and thereby demonstrate that quantitative analyses such as the ones used here are a powerful tool to gain novel insights into the evolution and diversity of flowers.
authors.affiliation: Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030 Vienna, Austria chartier.marion@gmail.com.
authors.forename: Marion
authors.identifier: http://orcid.org/0000-0001-6757-4760
authors.initials: M
authors.lastname: Chartier
authors.affiliation: Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030 Vienna, Austria.|Department of Ecology, Environment and Plant Sciences, Stockholm University, SE-106 91 Stockholm, Sweden.
authors.forename: Stefan
authors.initials: S
authors.lastname: Löfstrand
authors.affiliation: Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030 Vienna, Austria.
authors.forename: Maria
authors.initials: M
authors.lastname: von Balthazar
authors.affiliation: Muséum national d'Histoire naturelle, Institut de Systématique, Évolution, Biodiversité, UMR 7205 ISYEB MNHN/CNRS/UPMC/EPHE, 57 rue Cuvier, CP 39, 75005 Paris, France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Gerber
authors.affiliation: Muséum national d'Histoire naturelle, Institut de Systématique, Évolution, Biodiversité, UMR 7205 ISYEB MNHN/CNRS/UPMC/EPHE, 57 rue Cuvier, CP 39, 75005 Paris, France.
authors.forename: Florian
authors.initials: F
authors.lastname: Jabbour
authors.affiliation: Laboratoire Écologie, Systématique, Évolution, Université Paris-Sud, CNRS UMR 8079, 91405 Orsay, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Sauquet
authors.affiliation: Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030 Vienna, Austria juerg.schoenenberger@univie.ac.at.
authors.forename: Jürg
authors.initials: J
authors.lastname: Schönenberger
mesh_terms: D005075:Biological Evolution; D035264:Flowers / Q000502:physiology*; D019684:Magnoliopsida; D010802:Phylogeny
keywords: Ericales; disparity; flower morphology; fossils; functional modules; morphospace