Iriarteeae comprise five genera and 32 species and includes keystone species essential for forest structure and ecological assembly such as Iriartea deltoidea and Socratea exorrhiza. The tribe is found in lowland to mid-elevation forests from Nicaragua to Bolivia and from the Pacific coast of South America to the eastern flanks of the Andes and east into the Guiana Shield. To understand the evolutionary relationships within Iriarteeae our sampling focused on the entire biogeographic distribution of each of the species with 93% of sampled species represented by two or more individuals. We generated sequence data for 11 loci (5 chloroplast and 6 nuclear) to reconstruct a coalescent species tree and infer relationships amongst genera and species to, in turn, allow for tests of biogeography and community phylogenetics in the tribe. Our results define inter-generic relationships and resolve all genera as strongly supported monophyletic groups. The patterns of lineage diversification correspond to Andean orogeny and the formation of the Amazon basin. A description of the fossil pollen record is presented and compared with the phylogenetic results for a holistic interpretation of the biogeographic evolution of Iriarteeae. We also highlight the Andean radiation of Wettinia and the derivation of Amazonian lineages within the genus.
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International Conference on Comarative Biology of Monocotyledons, 2013