ID: 613 / 17

Category: Symposia

Track: Pending

Proposed Symposium Title: CAREX: THE EVOLUTION OF A MEGADIVERSE GENUS TACKLED FROM MULTIPLE APPROACHES

Abstract: Among sedges (Cyperaceae), Carex raises up as a megadiverse genus comprising about 2000 species (the richest in the family) and present in all continents except Antarctica. Species diversity follows an inverted latitudinal gradient, with higher species diversity in cold-temperate areas of the Northern Hemisphere. Eastern Asia has been pointed out as the center of origin and cradle of diversification, gathering some of the few Carex groups with truly entomophilous traits (e.g. Carex section Siderostictae). Most Carex species lack any evident dispersal syndrome that could have promoted its cosmopolitan distribution. Nonetheless, species from section Uncinia displays a unique exerted and hooked rachilla that might have acted as a successful device for long distance dispersal by epizoochory. Several independent colonization events of the Southern Hemisphere mostly from Asia and North America have been detected in Carex. These colonizing lineages have apparently conserved its ecological niche, and some of them have yielded putative evolutionary radiations, but it is not clear if these are linked to biotic (e.g. ecomorphological key innovations) or abiotic factors (e.g. climatic changes or physical isolation). In addition, there is still lack of information regarding the biogeographic history of multiple lineages within Carex (e.g. routes of dispersal, timing, vectors). It is also necessary to investigate the diversification mechanisms that explain differences in Carex diversity patterns both within and between lineages and regions. Our current knowledge of the overall phylogenetic relationships within the genus is reasonably good, but more limited at shallower evolutionary levels. All these characteristics (high taxonomic diversity, wide geographical distribution, documented radiations, and robust phylogenetic framework) make Carex an ideal model to evaluate hypotheses of diversification in different scenarios. The proposed symposium will navigate through the current advances in relation with the systematics, biogeography and diversification of Carex in different continents.

Speaker 1: Name: Étienne Léveillé-Bourret (Assistant Professor) Institutional affiliation: Institut de Recherche en Biologie Végétale, Université de Montréal, Montréal, Canada. Email: etienne.leveille-bourret@umontreal.ca Tentative talk title: Systematics and evolution of the Hirta Clade of Carex

Speaker 2: Name: Paulo Muñoz-Schüler (PhD student) Institutional affiliation: University of Concepción, Department of Botany, Concepción, Chile Email: paulomschuler@gmail.com Tentative talk title: Reaching the far-off sea: the hooked sedge (Carex sect. Uncinia) colonization of Pacific and Subantarctic archipelagos

Speaker 3: Name: Kyong-Sook Chung. (Associate Professor) Institutional affiliation: Department of Medicinal Plant Science, Jungwon University, Goesan 28024, Korea South Korea Email: kchung@jwu.ac.kr Tentative talk title: Systematics of Carex sect. Siderosticta

Topics (Up to three): Systematics

Topic 2: Phylogenetics and Phylogenomics

Topic 3: Biogeography / Phylogeography

Justification: The investigation of the systematics, biogeography and possible diversification causes of a megadiverse genus as Carex may be tackled from multiple approaches. Our symposium bridges several of the proposed topics, and encourages the use of novel analytical approaches. The proposed speakers have been carefully selected to fit the diversity criteria in terms of gender, career stage and geographic origin. These criteria will be further considered for the selection of potential additional speakers if the symposium is accepted. This symposium is organised by the International Sedge Society as part of the meeting we will have within the IBC.