Format: ORAL

Alexander Zizka1,2,5, Renske Onstein2,3 Frederic Lens2,4

1 Department of Biology, Philipps-University Marburg, Marburg, Germany 2 Naturalis Biodiversity Center, Leiden, The Netherlands 3 German Centre for Integrative Biodiversity Research Halle-Jena-Leipzig (iDiv), Leipzig, Germany 4 Institute of Biology Leiden, Leiden University, Leiden, The Netherlands 5 Email: alexander.zizka@biologie.uni-marburg.de

The repeated evolution of woodiness in herbaceous lineages has long been perceived as defining feature of island floras, in particular in the Tropics and sub-Tropics (insular woodiness). However, scattered evidence indicated comparable transitions of herbaceous lineages towards woody growth on continents, for instance on tropical mountains (derived woodiness). Here, we contrast recent results on the evolution of insular woodiness with a novel dataset on derived woodiness on continents. We identified numerous independent transitions towards woodiness in 57 eudicot angiosperm families, resulting in more than 6,500 recent derived woody species. We found more transitions and derived woody species on continents than on islands but derived woodiness on islands was more common when accounting for total angiosperm richness (on average 0.77% of the total flora on continents vs 1.85% on islands). Furthermore, we identified four global continental centers of derived woodiness, mostly in the Tropics and sub-Tropics: The Andes, South Africa, parts of Australia and New Zealand (Australasia ), and the Old-World dry belt. Our results reveal the re-evolution of woodiness in herbaceous lineages as widespread phenomenon on island and on continents driven globally by environmental conditions, albeit with important regional and systematic idiosyncrasies.