01974nas a2200133   4500008004100000245009900041210006900140300001200209490000700221520153000228100001701758700002101775856004401796       2010                        eng d00aThe oaks of western Eurasia: Traditional classifications and evidence from two nuclear markers0 aoaks of western Eurasia Traditional classifications and evidence  a351-3660 v593 aPhylogenetic relationships among species of Quercus (oaks) from western Eurasia including the western part of the Himalayas are examined for the first time. Based on ITS and 5S-IGS data three major infrageneric groups are recognized for western Eurasia: the cerroid, iliciod, and roburoid oaks. While individuals of the cerroid and ilicoid groups cluster according to their species, particularly in the 5S-IGS analyses, individuals of species of roburoid oaks do not cluster with exception of Quercus pontica. The Cypriot endemic Quercus alnifolia belongs to the ilicoid oaks, in contrast to traditional views placing it within the cerroid oaks. Based on all ITS data available, the groups identified for western Eurasia can be integrated into a global infrageneric framework for Quercus. The Ilex group is resurrected as a well-defined group that comprises taxa traditionally placed into six subsections of Q. sects. Cerris and Lepidobalanus (white oaks) sensu Camus. Phylogenetic reconstructions suggest two major lineages within Quercus, each consisting of three infrageneric groups. Within the first lineage, the Quercus group (roburoid oaks in western Eurasia) and the Lobatae group evolved by “budding” as is reflected by incomplete lineage sorting, high variability within groups, and low differentiation among groups. The groups of the second lineage, including the Cyclobalanopsis, Cerris (cerroid oaks in western Eurasia), and Ilex (ilicoid oaks in western Eurasia) groups, evolved in a more tree-like fashion. 1 aDenk, Thomas1 aGrimm, Guido, W.  uhttps://quercus.myspecies.info/node/12401825nas a2200157   4500008004100000245010900041210006900150260002100219300001200240490000700252520130200259100001701561700002401578700002101602856004401623       2010                        eng d00aEpisodic migration of oaks to Iceland: Evidence for a North Atlantic "land bridge" in the latest Miocene0 aEpisodic migration of oaks to Iceland Evidence for a North Atlan  cFebruary 1, 2010  a276-2870 v973 aDating the subsidence history of the North Atlantic Land Bridge (NALB) is crucial for understanding intercontinental disjunctions of northern temperate trees. Traditionally, the NALB has been assumed to have functioned as a corridor for plant migration only during the early Cenozoic, but recent findings of plant fossils and inferences from molecular studies are challenging this view. Here, we report dispersed pollen of Quercus from Late Miocene sediments in Iceland that shows affinities with extant northern hemispheric white oaks and North American red oaks. Older (15 to 10 Ma) sediments do not contain pollen of Quercus suggesting it arrived after that time. Pollen from the 9-8 Ma Hrutagil locality is indistinguishable from morphotypes common among white and red oaks. In contrast, pollen from the 5.5 Ma Selargil locality has a tectum that is at present confined to North American white and red oaks, indicating a second episode of migration to Iceland. These findings suggest that transatlantic migration of temperate plant taxa may not have been limited by vast areas of sea or by cold climates during the Miocene. Furthermore, our results offer a plausible explanation for the remarkably low degree of genetic differentiation between modern disjunct European and North American oaks.1 aDenk, Thomas1 aGrimsson, Frithgeir1 aZetter, Reinhard  uhttps://quercus.myspecies.info/node/125