New floristic data of alien vascular plants from Sicily

New records of Commelina communis, Euphorbia hypericifolia, Melia azedarach, Nicotiana tabacum, and Xanthoceras sorbifolium are reported for the Sicilian flora

Predicted HST FOC and broad band colours for young and intermediate Simple Stellar Populations

This paper presents theoretical HST and broad band colours from population synthesis models based on an homogeneous set of stellar evolutionary tracks as computed under canonical (no overshooting) assumptions, covering the range of cluster ages from t=8 Myr to t=5 Gyr for three different metallicities (Z=0.02, 0.006, and 0.001). Statistical fluctuations in the cluster population have been investigated, assessing the predicted fluctuations of the various colours as a function of the cluster integrated absolute magnitude. We show that the red leak in HST UV filters deeply affects the predicted fluxes and colours. However, we find that for F152M-F307M < 0.5 and for F170M-F278M < 0.5 (which means ages lower than 1 Gyr) the HST UV colours can still be used to infer reliable indications on the age of distant clusters. Moreover, one finds that the age calibration of these colours is scarcely affected by the amount of original helium or by the assumed IMF. On this basis, we present a calibration of the HST UV two-colours (F152M-F307M vs F170M-F278M) in terms of cluster ages for the three above quoted metallicities. We suggest the combined use of HST UV colours and IR colours (V-K in particular) to disentangle the metallicity-age effect in integrated colours of young stellar populations (t< 1 Gyr).Comment: Latex 18 pages, 16 encapsulated figures, 6 tables, A&ASS accepte

Synthetic Stellar Clusters for Pop III

We present preliminary results of an incoming theoretical work concerning the integrated properties of the Population III clusters of stars. On the basis of synthetic Color-Magnitude Diagrams, we provide a grid of optical and near-IR colors of Simple Stellar Populations with very low metallicity (Z=10$^{-10}$ and Z=10$^{-6}$) and age which spans from 10 Myr to 15 Gyr. A comparison with higher metallicities up to 0.006 is also shown, disclosing sizable differences in the CMD morphology, integrated colors and Spectral Energy Distribution (SED).Comment: 2 pages, incl. 2 figures, "The First Stars", Proceedings of the second MPA/ESO workshop, Eds.: Weiss, Abel, Hill, Springer, Heidelberg, 200

On the observational properties of He-burning stars: some clues on the tilt of the HB in metal rich clusters

We investigate the predicted Color-Magnitude distribution of metal-rich Horizontal Branch (HB) stars, discussing selected theoretical models computed under various assumptions about the star metallicity and the efficiency of super-adiabatic convection. We find that canonical Zero Age Horizontal Branches with metallicity larger or of the order of Z=0.002 should be all affected by a tilt, by an amount which increases when the metallicity is increased and/or the mixing length is decreased, reaching a tilt of $\Delta V \sim$0.2 mag in the case of solar metallicity when a mixing length value $\alpha$=1.6 is assumed ($\Delta V$ is the magnitude difference between the top of the blue HB and the fainter magnitude reached by the red HB). Uncertainties in the luminosity of the red HB due to uncertainty in the mixing length value are discussed. We finally discuss the much larger tilt observed in the clusters NGC 6441 and NGC 6388, reporting additional evidence against suggested non-canonical evolutionary scenarios. Numerical experiments show that differential reddening could produce such sloped HBs. Further, HST-PC imaging of NGC 6441 gives clear indications about the occurrence of differential reddening across the cluster. However, the same imaging shows that the observed slope of the red HB {\em is not} an artifact of differential reddening. We finally show that sloping red HBs in metal rich clusters are a common occurrence not necessarily correlated with the appearance of extended blue HB.Comment: 14 pages, 9 figures, Accepted by Ap

VERBENA BONARIENSIS (VERBENACEAE) ADVENTIVE IN ITALY

Among the species of Verbena L. cultivated in Italy Traverso (1) reports: V venosa Gilles, V tenera Sprengel (= V. pulchella Sweet.) and the horticultural hybrid V I?Jbrida Hort. (=V. hortensis Hort.). No trace of V. bonariensis L., that is reported about 60 years later as naturalized in Tuscany (2). In the Herbarium Centrale !talcum (Fl) are housed specimens collected in Piedmont and Tuscany, labelled as V. venosa - taxon considered a variety of V. bonariensis. V. bonariensis, as indicated by the specific epithet, is a South American species, herbaceous, usually perennial, also cultivated as an ornamental. Several varieties and wild lforms are known of this taxon. The International Plant Names Index (IPNI) records: V bonariensis f. albiflora Moldenke, V. bonariensis var. brevibracteata Kuntze, V. bonariensis var. conglomerata Briq., V bonariensis f. gracilis (Cham.) Voss., V. bonariensis var. hispida Moldenke, V. bonariensis var. litoralis Hook., V. bonariensis var. longibradt?ata Kuntze, V. bonariensis var. rigida (Spreng.) Kuntz, V. bonariensis f. robustior Chodat, V bonariensis f. venosa (Gillies & Hook.) V oss. This species is native of S. America (Argentina, Brasile, ]Paraguay and Uruguay) (3, 4) and introduced in the USA (5), Azores, Great Britain, Canary Islands, Portugal, Madeira (6) and in Italy, as reported above, in Tuscany, in Tombolo Pisano (PI) (2, 7, 8) and in Liguria (8). Some considerations on the tendency of naturalization of the species in Sicily (9) where accidentally misinterpreted as the report of naturalization in the region (10, 11). This record was neglected in the subsequent floras and checklists (7, 8, 12, 13). Recently we verified the spontaneous occurrence of v~ bonariensis at the edges of a channel, in the southern outskirts of the city of Palermo (Sicily). This population, referred to V. bonariensis var. hispida, is made up of about 100 vigorous and perennial individuals with tendency to expand, actually, in the same area. The taxonomic identity of the Tuscan populations is different. In this region, it is known from Tombolo Pisano (2) as well as from Florence as documented by specimens collected in the square in front of the rail station of S. Maria Novella (Raimondo et Domina, 21/06/2012, PAL), in the fenced area for works of rearrangement of the square. In comparison with the population from Tombolo Pisano, referred to the nominal type, the population from Florence looks like annual and belonging to a diffe1rent variety, also in comparison with the Sicilian one. The recent discovery in Sicily as well as increasing the 11uota of adventitious exotic vascular flora of the island, confirms the tendency of the species to spread further in. the national territory

New Aloes casual aliens in Sicily

Aloë arborescens, A. brachystachys and A. maculata (Asphodelaceae) are reported for the first time as casual aliens in Sicily. A. brachystachys is new also for the alien flora of Italy

Taxonomic remarks and distribution of Smyrnium dimartinoi (Apiaceae)

Smyrnium L., an Eurasian genus of the family Apiaceae, includes about 20 taxa of which only 7 are accepted at specific rank; among these, 5 are native to Europe (Tutin & al. 1968; Gomez 2003). In the Italian flora, the genus is represented by 3 taxa also occurring in Sicily (Pignatti 1982; Giardina & al. 2007); these are Smyrnium olusatrum L., S. perfoliatum L. and S. rotundifolium Mill. The last one has also been treated at the rank of subspecies under S. perfoliatum [S. perfoliatum subsp. rotundifolium (Mill.) Hartvig] (Strid 1986; Conti & al. 2005), or as a variety [S. perfoliatum var. rotundifolium (Mill.)Fiori (Fiori 1925)]. In Sicily, same populations related to S. perfoliatum differ from this taxon for both morphological and ecological characteristics, especially on the Madonie Mountains and the Mountains around Palermo. The study of the morphological characteristics \u2013 namely of the root, stem, and leaf \u2013 allowed to clearly distinguish these populations that, therefore, represented a taxonomically and perhaps even chorologically critical case, since similar plants occurring in Greece were described as S. rotundifolium var. ovatifolium Hal\ue1csy (Hal\ue1csy 1901). In Sicily the same population was finally described as a new species named Smyrnium dimartinoi (Raimondo et al., 2015) to commemorate Andrea Di Martino (1926-2009), professor of botany and director of the Botanical Garden and Herbarium Mediterraneum in the Palermo University. The occurrence of the new taxon related to S. perfoliatum \u2013 ascertained only in Central-Western Sicily and in Crete \u2013 has also been supposed in other countries of the Mediterranean Europe; this, owing to some critical specimens observed in PAL and PAL-Gr. In this contribution, the analytical key of S. perfoliatum group is presented. Furthermore, the geographical distribution of S. dimartinoi is specified after the study of selected exsiccata from other Italian and foreign herbaria. The results found in this research show that S. dimartinoi belongs to the Eurimediterranean element, spread in various countries of the Southern Europe, from Greece to Italy and Spain