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Morphophysiological dormancy was investigated in seeds of Ribes multiflorum Kit ex Roem et Schult. ssp. sandalioticum Arrigoni, a rare mountain species endemic to Sardinia (Italy). There were no differences in imbibition rates between intact and scarified seeds, suggesting a lack of physical dormancy, while methylene blue solution (0.5%) highlighted a preferential pathway for solution entrance through the raphe. Embryos were small at seed dispersal, with an initial embryo:seed ratio (E:S) of ca. 0.2 (embryo length, ca. 0.5 mm), whereas the critical E:S ratio for germination was three times longer (ca. 0.6). Gibberellic acid (GA(3), 250 mg · l(-1)) and warm stratification (25 °C for 3 months) followed by low temperature (<15 °C) enhanced embryo growth rate (maximum of ca. 0.04 mm · day(-1) at 10 °C) and subsequent seed germination (radicle emergence; ca. 80% at 10 °C). Low germination occurred at warmer temperatures, and cold stratification (5 °C for 3 months) induced secondary dormancy. After radicle emergence, epicotyl emergence was delayed for ca. 2 months for seeds from three different populations. Mean time of epicotyl emergence was affected by GA(3) . Seeds of this species showed non-deep simple (root) - non-deep simple (epicotyl) morphophysiological dormancy, highlighting a high synchronisation with Mediterranean seasonality in all the investigated populations., (© 2011 German Botanical Society and The Royal Botanical Society of the Netherlands.)

Phylogenetic analyses of three cpDNA markers (matK, rpl16, and trnL-trnF) were performed to evaluate previous treatments of Ruteae based on morphology and phytochemistry that contradicted each other, especially regarding the taxonomic status of Haplophyllum and Dictamnus. Trees derived from morphological, phytochemical, and molecular datasets of Ruteae were then compared to look for possible patterns of agreement among them. Furthermore, non-molecular characters were mapped on the molecular phylogeny to identify uniquely derived states and patterns of homoplasy in the morphological and phytochemical datasets. The phylogenetic analyses determined that Haplophyllum and Ruta form reciprocally exclusive monophyletic groups and that Dictamnus is not closely related to the other genera of Ruteae. The different types of datasets were partly incongruent with each other. The discordant phylogenetic patterns between the phytochemical and molecular trees might be best explained in terms of convergence in secondary chemical compounds. Finally, only a few non-molecular synapomorphies provided support for the clades of the molecular tree, while most of the morphological characters traditionally used for taxonomic purposes were found to be homoplasious. Within the context of the phylogenetic relationships supported by molecular data, Ruta, the type genus for the family, can only be diagnosed by using a combination of plesiomorphic, homoplasious, and autapomorphic morphological character states.

Despite the remarkable species richness of the Mediterranean flora and its well-known geological history, few studies have investigated its temporal and spatial origins. Most importantly, the relative contribution of geological processes and long-distance dispersal to the composition of contemporary Mediterranean biotas remains largely unknown. We used phylogenetic analyses of sequences from six chloroplast DNA markers, Bayesian dating methods, and ancestral area reconstructions, in combination with paleogeographic, paleoclimatic, and ecological evidence, to elucidate the time frame and biogeographic events associated with the diversification of Araceae in the Mediterranean Basin. We focused on the origin of four species, Ambrosina bassii, Biarum dispar, Helicodiceros muscivorus, Arum pictum, subendemic or endemic to Corsica, Sardinia, and the Balearic Archipelago. The results support two main invasions of the Mediterranean Basin by the Araceae, one from an area connecting North America and Eurasia in the Late Cretaceous and one from the Anatolian microplate in western Asia during the Late Eocene, thus confirming the proposed heterogeneous origins of the Mediterranean flora. The subendemic Ambrosina bassii and Biarum dispar likely diverged sympatrically from their widespread Mediterranean sister clades in the Early-Middle Eocene and Early-Middle Miocene, respectively. Combined evidence corroborates a relictual origin for the endemic Helicodiceros muscivorus and Arum pictum, the former apparently representing the first documented case of vicariance driven by the initial splitting of the Hercynian belt in the Early Oligocene. A recurrent theme emerging from our analyses is that land connections and interruptions, caused by repeated cycles of marine transgressions-regressions between the Tethys and Paratethys, favored geodispersalist expansion of biotic ranges from western Asia into the western Mediterranean Basin and subsequent allopatric speciation at different points in time from the Late Eocene to the Late Oligocene.