Carex (Cyperaceae) in South America: diversity, phylogenetics and biogeography of a Boreotemperate element in the Neotropics

PEDRO JIMÉNEZ-MEJÍAS; CARMEN BENÍTEZ-BENÍTEZ; HAMILTON BELTRÁN; ASUNCIÓN CANO; SABINA DONADÍO; MARCIAL ESCUDERO; SEBASTIAN GEBAUER; ANDREW HIPP; MÓNICA MÍGUEZ; ROBERT NACZI; ANTON REZNICEK; ERIC ROALSON; JOSE IGNACIO MÁRQUEZ CORRO; TAMARA VILLAVERDE; LAURENCE DORR; SANTIAGO MARTÍN-BRAVO; MODESTO LUCEÑO

Natal

Conferencia; 6th International Conference on Comparative Biology of Monocotyledons - Monocots VI; 2018

Universidade Federal do Rio Grande do Norte

With about 2000 spp, Carex (Cyperaceae) is the largest monocot genus and one of the three largest angiosperm genera. Originated in eastern Asia during the Oligocene, its current distribution is cosmopolitan. Remarkably, Carex has remained as a temperate-cold element during its entire radiation, being absent from true tropical forests and deserts. Here we analyze the diversity patterns and phylogenetic and biogeographic history of Carex in South America. The subcontinent harbors 215 species (11% of the total), belonging to the four major clades of the genus and 40 sections (>25%). Phylogenies point to multiple colonization events, mostly from North America, but also involving long-distance dispersal from the Western Palaearctic and Australasia. Typical patterns of distribution include North-South Andean and East-West temperate South Cone disjunctions within the continent, and bipolar and trans-Caribbean disjunctions between North and South America. Most groups seem to have undergone in situ diversification. Preliminary diversification analyses show that the innovation of a hooked fructification in the species of the former genus Uncinia, may have contributed to triggering the diversification of the group in South America, although additional factors may need to be invoked to explain such findings.