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The new species, Thliphthisa sapphus sp. nov. (Rubiaceae, Rubieae), a narrow endemic of the white cliffs of Lefkátas on the southwest coast of Lefkada (Greece) is described and illustrated and an IUCN assessment is presented. Vegetation relevés were performed at the single known locality, limestone cliffs facing the sea and revealed a new association, the Thliphthisa sapphus-Lomelosietum dallaportae. The chromosome number of Thliphthisa sapphus was determined as 2n = 4x = 44, being the single tetraploid species in the genus to date. The species also differs markedly morphologically from its morphologically closest relatives, two Greek steno-endemic oreophytes, Th. baenitzii and Th. muscosa by the following characters: densely setose mericarps and corolla, tetraploidy and by its distribution. An identification key for the Greek species of Thliphthisa is provided. Th. sapphus constitutes the westernmost outpost of a group of Greek steno-endemics, highlighting the importance of coastal habitats and their protection as refugia for poorly competitive chamaephytes. [ABSTRACT FROM AUTHOR]

The Balkan Peninsula as one of Europe's biodiversity hotspots came into the focus of biogeographic research during the last decade, but the phylogeography of its mountain flora still remains widely unexplored. To investigate historical and future range dynamics within Gentianella crispata, a typical plant of mountainous grasslands sub-endemic to the Balkan Peninsula with a single known population in southern Italy, we combine molecular analyses based on cpDNA sequence and amplified fragment length polymorphism data with species distribution models. In the western Balkan, we found a distinctly separated cluster at the northern edge of the species' distribution range. The split towards the less structured southern populations is located at the Neretva canyon, a pattern repeatedly reported before. This finding is clearly in line with the refugia-within-refugia hypothesis assuming more than one Pleistocene refugium on the Balkan Peninsula. The Italian population was found to be closely related to populations in the central to southern Dinaric mountains indicating a recent, possibly human-mediated migration event. Niche models for future climate scenarios forecast a severe loss of climatically suitable areas, especially in the southern parts of the range, pointing at deteriorating effects of climate warming for those mountainous grassland habitats in southern Europe, which harbour G. crispata. [ABSTRACT FROM AUTHOR]

Reproductive interactions among cytotypes in their contact zones determine whether these cytotypes can co-exist and form stable contact zones or not. In autopolyploids, heteroploid cross-compatibilities might depend on parental ploidy, but tests of this hypothesis in autopolyploid systems with more than two ploidies are lacking. Here, we study Jacobaea carniolica, which comprises diploid, tetraploid, and hexaploid individuals regularly forming contact zones. Seeds obtained from in situ cross-pollinations within and among cytotypes were subjected to DNA flow cytometry and greenhouse germination experiments. Hybrid fitness and parental effects on hybrid fitness were tested with regression models comparing fitness parameters of early life stages. Irrespective of the direction of crosses, seed viability and seedling survival in diploid-polyploid crosses were substantially lower than in tetraploid-hexaploid crosses. In contrast, seedling growth traits indicated neither transgressive character expression nor any selection against hybrid offspring. Congruent with a model of genome dosage effects, these traits differed between reciprocal crosses, especially of diploids and tetraploids, where trait values resembled those of the maternal parent. The strong effect of parental ploidy on offspring fitness in heteroploid crosses may cause contact zones involving exclusively polyploid cytotypes to be less stable over longer terms than those involving diploids and polyploids. [ABSTRACT FROM AUTHOR]

The new species, Thliphthisasapphus sp. nov. (Rubiaceae, Rubieae), a narrow endemic of the white cliffs of Lefkátas on the southwest coast of Lefkada (Greece) is described and illustrated and an IUCN assessment is presented. Vegetation relevés were performed at the single known locality, limestone cliffs facing the sea and revealed a new association, the Thliphthisasapphus - Lomelosietumdallaportae . The chromosome number of Thliphthisasapphus was determined as 2 n = 4 x = 44, being the single tetraploid species in the genus to date. The species also differs markedly morphologically from its morphologically closest relatives, two Greek steno-endemic oreophytes, Th.baenitzii and Th.muscosa by the following characters: densely setose mericarps and corolla, tetraploidy and by its distribution. An identification key for the Greek species of Thliphthisa is provided. Th.sapphus constitutes the westernmost outpost of a group of Greek steno-endemics, highlighting the importance of coastal habitats and their protection as refugia for poorly competitive chamaephytes., Competing Interests: The authors have declared that no competing interests exist., (Walter Gutermann, Tae-Soo Jang, Arndt Kästner, David Prehsler, Dieter Reich, Andreas Berger, Ruth Flatscher, Christian Gilli, Markus Hofbauer, Margarita Lachmayer, Ruth Sander, Michaela Sonnleitner, Ladislav Mucina.)

In order to uncover patterns and processes of segregation of co-existing cytotypes, we investigated a zone in the eastern Alps (Austria) where diploid and hexaploid individuals of the alpine herb Senecio carniolicus Willd. (Asteraceae) co-occur. Linking the fine-scale distribution of cytotypes to environmental and spatial factors revealed segregation along an ecological gradient, which was also reflected in the cytotype-associated plant assemblages. Compared to diploids, hexaploids are found in more species-rich and denser communities. This may be due to their better competitive ability and lower tolerance of abiotic stress compared to the diploids. The lack of any intermediate cytotypes suggests the presence of strong reproductive isolation mechanisms, whose nature is, however, elusive.