We present the results of a study aimed at developing a vegetation map of Sicily (Italy) including the smaller circum-Sicilian islands, for an area of approximately 25,703 km 2 . The work is a synthesis of studies carried out in accordance with the survey methodology of phytosociology in the last 40 years over the whole study area. The vegetation map of Sicily was compiled in a Geographical Information Systems (GIS) environment, in order to produce a cartographic representation at a scale of 1:10,000 (reduced to a scale of 1:250,000). The physiognomic-structural characteristics of the plant landscape of Sicily are analyzed, providing a general and, at the same time, detailed overview of the phytocoenotic aspects represented on the territory, as well as of the relative bibliographic references. At the reference scale, 36 types are represented, 16 of which are related to zonal vegetation (Mediterranean maquis, Quercus ilex woods, Quercus suber woods, Castanea sativa woods, Quercus pubescens deciduous woods, mesophilous deciduous woods, Fagus sylvatica woods, Betula aetnensis woods, woods dominated by woody gymnosperms, forest edge shrubs, orophilous pulvinate shrubs, shrublands and garrigues, Ampelodesmos mauritanicus grasslands, mesophilous and sub-hygrophilous grasslands and pastures), 11 are related to azonal vegetation (riparian, psammophilous herbaceous, chasmo-halophitic, etc.) and 9 are related to anthropogenic vegetation (arable lands and extensive herbaceous crops, vineyards, olive groves and dry cultivation mosaics, hazelnut groves, irrigated citrus groves and orchards, greenhouses, built-up areas). ARTICLE HISTORY

A phytosociological study was done of Laurus nobilis woodlands in Sicily. The analysis, based on 18 relevés, supports\ud the definition of a new syntaxon (Acantho mollis-Lauretum nobilis ass. nov.), considered as a vicariant of similar vegetation\ud aspects described in other Mediterranean areas (Iberian and Italian peninsulas). The study mainly includes some unpublished\ud sites where polycormic individuals of laurel, sometimes reaching 13-15 meters in height, dominates the tree layer. This\ud vegetation is also characterized by some laurophyllous species (Hedera helix, Rhamnus alaternus, Smilax aspera and sometimes\ud Viburnum tinus) and lianas (Rubia peregrina var. longifolia, Asparagus acutifolius, Tamus communis, Clematis\ud vitalba, Calystegia sylvatica and Rubus ulmifolius), while in the undergrowth comprises particularly various broadleaved\ud elements such as Cyclamen hederifolium subsp. confusum, and Acanthus mollis subsp. mollis, both included in the characteristic\ud species combination together with Pistacia terebinthus and Orobanche hederae. The coenosis is typical of the\ud humic soils, often rich in lithic components, of shaded ravines and peririparian environments, in the thermo- and mesomediterranean\ud thermotype (Mediterranean pluviseasonal oceanic bioclimate). In view of the relictual status of this vegetation\ud - also included as a "Priority Habitat" in Council Directive 92/43/EEC - we underline the need for a suitable protection\ud and conservation of these small, fragmented and isolated patches.\ud Keywords: Laurus nobilis matorral, Quercetea ilicis, Mediterranean region, relic vegetation

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Petagnaea gussonei (Apiaceae) is an endangered species endemic to the Nebrodi mountains (north-eastern Sicily). Although an increasing number of studies have been performed on this species, its reproductive biology remains poorly understood. The aim of this study was to investigate in detail the structure of the flower and the fruit of Petagnaea, and the possible implications for its breeding system and seed dispersal mechanism. Results from fieldwork, light microscopy and scanning electron microscopy suggest (1) the presence of protandrous hermaphrodite flowers; (2) geitonogamy, autogamy, and allogamy as breeding system mechanisms of P. gussonei, even if asexual reproduction is preferred by the plant; and (3) epizoochory and hydrochory as possible modalities of fruit dispersal.

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Our investigation aims to understand the genetic structure and evolutionary history of Petagnaea gussonei, an ancient and endangered species belonging to the Saniculoideae subfamily (Apiaceae). It is paleoendemic to Sicily, with a small number of populations in the Nebrodi Mountains. A\ud total of seven chloroplast microsatellite repeat loci and 12 AFLP primer combinations were used to screen 115 individuals\ud corresponding to 17 populations. The ratio of seed to pollen flow was also calculated using the modified Ennos equation. A relatively high level of genetic diversity was detected with AFLPs (e.g., 0.045\H\0.278), and a moderate variation was also found using cpSSRs (0\Hk\0.667). Two different haplotypes (B and W) were\ud identified, with five populations being monomorphic for haplotype B. There was no genetic differentiation on the basis\ud of haplotypic frequency (GST) and similarity (RST), and no phylogeographic structure was detected among the populations. AFLP values also confirmed that the populations are\ud not very genetically differentiated. The principal component analysis based on pairwise genetic differences showed three\ud groupings without a geographical correlation. The AMOVA analysis indicates that theamount of variation is higher within\ud populations (82 %) than among populations (18 %). Results of the pollen flow/seed flow ratio indicated positive values for\ud each population, indicating that gene flow by seed is not more efficient than by pollen. Instead, the total pollen/seed flow for all population presents a negative value, suggesting that pollen dispersal does not appear to be more effective over the\ud long range for gene flow than seed dispersal. This differentiation level supports the hypothesis that the fragmentation and isolation of the residual populations is in progress. This\ud phenomenon is due not only to post-ice age climate changes, but also to direct and indirect anthropic actions

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Species identification within the species complex of Q. pubescens is a well-known taxonomic challenge among European botanists. Some of the specific pubescent oak binomials currently accepted in various European floras and checklists were originally described in Sicily and southern Calabria. As a consequence, several species belonging to the pubescent oaks group (Q. pubescens, Q. amplifolia, Q. congesta, Q. dalechampii, Q. leptobalana and Q. virgiliana) are reported in the taxonomic and phytosociological literature. To verify whether it was possible to associate a diverse set of morphological characters with each of these different taxa, thirteen natural populations of pubescent oak from Sicily and southern Calabria were sampled. A total of 391 trees, 3,887 leaves and 1,047 fruits were collected. Overall, 28 morphological characters of oak leaves and fruits were statistically analysed using univariate and multivariate procedures. The results showed that neither the groups of morphological diversity identified by cluster analysis, nor those obtained by our expert identification through the use of analytical keys, matched with the current taxonomical frameworks as proposed by the most recent floras and checklists. Nearly all of the morphological characters considered displayed a more or less continuous trend of variation, both within and among populations. In the light of these findings it seems unlikely that more than one biological species of pubescent oak occurs in Sicily and southern Calabria.