Identifying areas susceptible to invasion by an alien species is a strategy of prevention. We used national herbaria and global databases to assess the invasion trends of the two aquatic invasive species Ludwigia hexapetala and Ludwigia peploidessubsp. montevidensis in Italy. We defined the invasion status with invasions curves and predicted potentially suitable areas with Species Distribution Models based on WorldClim variables and the human footprint index. Low seasonal variation in temperature and precipitation, temperature ≥ 20 °C in the warmest, driest and wettest periods of the year and precipitation in the coldest period are the bioclimatic factors that most account for the potential distribution of the two species. The human footprint has lower relative importance than bioclimatic variables. All Italian peninsula appears as a suitable bioclimatic environment for the invasion of the two Ludwigia species, except the Alps and the highest peaks in the Apennine. Based on the current distribution of the species in Italy and the mostly densely invaded areas globally, the agricultural land surrounding the current invaded areas and along the Italian coasts is the most vulnerable to the invasion. Considering the trend of the invasion curves, which have been sharply rising for the latest decades, there are reasons to expect that the alien Ludwigia species will continue their expansion, if no timely and effective actions are taken. Informative campaigns, accurate monitoring and prompt management are fundamental preventive tools in areas predicted as vulnerable to invasion by this study.

Invasive alien species are among the main global drivers of biodiversity loss posing major challenges to nature conservation and to managers of protected areas. The present study applied a methodological framework that combined invasive Species Distribution Models, based on propagule pressure, abiotic and biotic factors for 14 invasive alien plants of Union concern in Italy, with the local interpretable model-agnostic explanation analysis aiming to map, evaluate and analyse the risk of plant invasions across the country, inside and outside the network of protected areas. Using a hierarchical invasive Species Distribution Model, we explored the combined effect of propagule pressure, abiotic and biotic factors on shaping invasive alien plant occurrence across three biogeographic regions (Alpine, Continental, and Mediterranean) and realms (terrestrial and aquatic) in Italy. We disentangled the role of propagule pressure, abiotic and biotic factors on invasive alien plant distribution and projected invasion risk maps. We compared the risk posed by invasive alien plants inside and outside protected areas. Invasive alien plant distribution varied across biogeographic regions and realms and unevenly threatens protected areas. As an alien's occurrence and risk on a national scale are linked with abiotic factors followed by propagule pressure, their local distribution in protected areas is shaped by propagule pressure and biotic filters. The proposed modelling framework for the assessment of the risk posed by invasive alien plants across spatial scales and under different protection regimes represents an attempt to fill the gap between theory and practice in conservation planning helping to identify scale, site, and species-specific priorities of management, monitoring and control actions. Based on solid theory and on free geographic information, it has great potential for application to wider networks of protected areas in the world and to any invasive alien plant, aiding improved management strategies claimed by the environmental legislation and national and global strategies.

We analysed the invasion history of two North American macrophytes (Elodea canadensis and E. nuttallii) in Italy, through an accurate census of all available herbarium and field records, dating between 1850 and 2019, and a rich literature collection describing the initial introduction and naturalisation phase that supports the results obtained by the occurrence records. Elodea canadensis arrived in Italy before 1866 and had two invasion phases, between the 1890s and 1920s and between the 1990s and 2000s; E. nuttallii, probably arrived in the 1970s, started invading in 2000 and the invasion is still ongoing. Botanical gardens and fish farming played a crucial role in dispersal and naturalisation of both species. The current invasion range of both species is centred in northern Italy, with scattered occurrences of E. canadensis in central and southern regions. River Po represents a dispersal barrier to the Mediterranean region and a strategic monitoring site to prevent the invasion in the peninsula. The study detects differences in the niches of the two species during the introduction and naturalisation phase and a habitat switch occurred after 1980 in E. canadensis and after 2000 in E. nuttallii, during their expansion phases. For E. canadensis the switch corresponds to the second invasion round. Further research can clarify whether the second invasion round is due to confusion of the recently introduced E. nuttallii with E. canadensis, to a cryptic introduction of a new genotype, to post-introduction evolution, or just to an increased scientific interest in biological invasions.

In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions, and status changes for Italy or for Italian administrative regions. Nomenclatural and distribution updates published elsewhere are provided as Suppl. material 1.

The current understanding of the richness and distribution of plant species on a national scale, achieved by the recent checklists of Italian flora, is largely based on the quality and thoroughness of the data provided by regional floristic studies. This knowledge benefits from regional databases, such as the Wikiplantbase #Liguria project, which offers an online platform where thousands of geo-referenced floristic records from Liguria (north-western Italy) are stored and freely accessible. In 2019, adopting a citizen science approach, a floristic survey program consisting of 11 excursions opened to the public was implemented, with the aim of deepening the floristic knowledge of some poorly investigated areas of the region. The active collaboration between scientists and volunteers led to the collection of about 4000 floristic data corresponding to more than 800 taxa, including 13 taxa unknown or no longer recorded for Liguria. These results suggest that citizen science can be a useful tool to address the knowledge gaps of regional floras. In particular, collaboration between experts and non-professional botanists allows to collect reliable data even for hardly-to-recognize taxa, contributing to fix some gaps occurring in the Wikiplantbase #Liguria project.

In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions, and status changes for Italy or for Italian administrative regions. Furthermore, three new combinations are proposed. Nomenclatural and distribution updates published elsewhere are provided as Suppl. material 1.

The census of the loci classici of 1,227 native, non-endemic vascular plants described from Italy is here presented and described. The effective place of publication of accepted names, basionyms and homotypic synonyms were identified and critically verified. The geographic information on the loci classici was excerpted from the protologues, as well as information on typification for the taxa described before 1 January 1958. The names without a holotype are 1,165. For 591 names a lecto- or neo-typification is available in literature, while 572 currently accepted taxa still need a type designation. For ten of these names showing previous ineffective typification, nomenclatural types are designated here (Allium savii, A. tenuiflorum, Anemone millefoliata, Catapodium tuberculosum, Cynosurus siculus, Filago congesta, Saponaria bellidifolia, Sclerochloa patens, S. zwierleinii, and Vicia leucantha). A new combination (Trisetaria aurea comb. nov.) is proposed. The general picture of the currently accepted taxa of vascular plants described from Italy, including endemics, amounts to 2,631, i.e. about 32% of the native flora currently recorded for the country.

In order to improve the floristic knowledge of the Italian territory, we report the inventory of the taxa collected during the annual field trip of the working group for Floristics, Systematics and Evolution of the Italian Botanical Society held in 2015 in eastern Irpinia and Vulture-Melfese area (South Italy). The investigated territories are located in southern Apennines, along the border between the Campania and Basilicata administrative regions. These areas are scarcely known in terms of vascular flora. The floristic samplings were performed in 19 sites selected as representative of the local environmental diversity as regards to climate, litho-morphology and land-use. The research led to the identification of 4,137 specimens of vascular plants, belonging to 815 species and subspecies, 399 genera, and 85 families. Among these taxa, 42 were endemic to Italy, 38 were included in the IUCN Red List of the Italian Flora, 28 were alien and 5 were cryptogenic in Campania and/or Basilicata administrative regions. Two taxa, Aquilegia coerulea (casual alien, native to North America) and Lolium × boucheanum (native), were found to be new for Italy. On the basis of the available floristic literature the first one is also to be considered new for the European flora. At regional scale, we have found 18 taxa new for the Campania and 15 new for the Basilicata region. Finally, 10 taxa were confirmed for Campania. Data obtained during this study, confirmed the important role of a collaborative approach among botanists and the great relevance of these territories for plant diversity.

In this contribution, new data concerning the distribution of vascular flora alien to Italy are presented. It includes new records, confirmations, exclusions, and status changes for Italy or for Italian administrative regions of taxa in the genera Bunias, Calocedrus, Calycanthus, Celosia, Clerodendrum, Convolvulus, Crassula, Cyclamen, Datura, Dicliptera, Eragrostis, Erigeron, Gamochaeta, Gazania, Impatiens, Kolkwitzia, Leucaena, Ludwigia, Medicago, Muscari, Nigella, Oenothera, Opuntia, Paulownia, Petroselinum, Phyllostachys, Physalis, Pseudosasa, Quercus, Reynoutria, Roldana, Saccharum, Sedum, Semiarundinaria, Senecio, Sisyrinchium, Solanum, Sporobolus, Tulipa, Vachellia, Verbena, and Youngia. Nomenclatural and distribution updates published elsewhere are provided as Suppl. material 1.

In 2014, the annual field trip of the working group for Floristics, Systematics, and Evolution of the Italian Botanical Society was held in Piemonte (northern Italy), at the head of the Po Valley. This valley, at whose extremity is located the Monviso (3,841 m a.s.l.), belongs to the Cottian Alps about which very little is known from a floristic point of view. An inventory of the taxa of vascular plants collected during the field trip is reported here. The research led to the identification of 3,546 exsiccata, kept in nine public and nine private collections. A total of 669 taxa belonging to 79 plant families were recorded. Six taxa resulted endemic to Italy and three exclusive to Piemonte, while only nine alien species were detected; six taxa are new and five confirmed for the regional flora.

Linum elegans has been detected in calcareous rocky garrigues on the Gargano promontory (Apulia, SE-Italy), representing the first record for the Italian flora and the first one outside the Balkan Peninsula. The geographical disjunction may provide evidence for past amphi-Adriatic/amphi-Ionic terrestrial connections. The population found was ascribed to L. campanulatum in the past. As a consequence, a comparison between these two species is undertaken. Furthermore, the name L. elegans is here lectotypified on a specimen preserved at G, and the IUCN assessment of the species in Italy is briefly discussed.

Limonium avei is an annual species occurring in the salt‐marshes and in limited surfaces of rocky areas around the Mediterranean coasts. Seed lots from five populations of this species, along a latitudinal gradient, were analyzed using an image analysis system to detect differences in seed morphology among populations. Germination requirements at constant (5–25°C) and alternating temperatures (25/10°C), both in light and in darkness, were evaluated for all populations, as well as the effect of the calyx removal on final seed germination and its rate. Morpho‐colorimetric analysis clearly identified seeds from different populations, habitats and substrates without misattributions among them. The calyx slowed the germination process, influencing both final germination and rate with respect to naked seeds. Seeds from all populations germinated with significantly higher percentages in the light, with respect to those incubated in the darkness, and showed rapid germination (time in days to reach 50% of germination: 0.5 days) at the warmer tested temperature (25°C). High germination (>80%) was also detected for seeds of all the investigated populations, except for those from the Apulian region (South Italy, ca. 60%). Our results highlight that L. avei has a high variability in seed morphology, probably habitat induced, and a fast germination response for all populations. Rapid germination may be an adaptive strategy that allows L. avei seeds to take advantage of transient favorable conditions during the germination stage, to ensure seedling establishment under the unpredictable rainfall pattern in the Mediterranean climate.

The loss of orchid habitats has increased the investment on orchid conservation efforts to reduce the risk of extinction of rare species. In northwestern Italy, orchids are among the most threatened of all plant groups in the region, but little is known about the biology of most of the less abundant taxa. In this study, we used light and scanning electron microscopy to characterize the morphology of the seeds of the threatened Orchis patens Desf., a declining species present in semi-natural habitats. We found a marked positive relationship between seed size and embryo size that may be not restricted to O. patens but also occur in other orchid species. The comparative analysis of the observed seed traits revealed hidden morphological affinities at the reproductive level among O. patens and the three subspecies of O. mascula, showing the potential of this approach to test the taxonomic relationships among the different taxa included in the genus Orchis.

We conducted a GIS spatial analysis with the aim of providing the first quantitative large-scale overview of the distribution patterns of 1536 type localities (loci classici) of 1216 Italian endemic vascular plants and their relationship with a set of descriptive variables. Whereas some variables were used to model the presence-absence distribution patterns of the type localities for the whole set of endemics as well as for the subset of narrow endemics, others (e.g., presence inside or outside protected areas and Italian Important Plant Areas) were considered with the purpose of assessing potential assets or risks for conservation.The largest number of type localities was found within the Mediterranean biogeographic region (1134), followed by the Alpine region (306) and Continental region (96). A total of 670 locations are located on islands, whereas 866 are located on the Italian mainland (139 and 124 in the case of narrow endemics, respectively). A large number of type localities are located in mountainous areas and along the coastline, which can be seen as a potential risk for conservation. On the contrary, we detected a positive correlation with the distance from roads, which might be considered to be an asset. Importantly, 1030 type localities fall inside protected areas, whereas 506 localities fall outside protected areas, with 259 of these unprotected localities on islands.We propose considering the results of the analysis of the distribution of type localities of Italian endemics to be a strategic tool for conservation planning and resource management. Application of plant micro-reserves and integration of diverse legislation tools are suggested to strengthen efforts and increase conservation success.

The inventory of the taxa collected during the annual field trip of the working group for Floristics Systematics and Evolution of the Italian Botanical Society is reported. It was held in 2013 along the Maddalena Mountains a mountain ridge of the southern Apennines located between the Basilicata and Campania administrative regions (southern Italy) considered as being poorly characterized in terms of vascular flora. A total of 701 units belonging to 74 plant families were recorded including two varieties and four hybrids.Thirty-five taxa resulted endemic to Italy and only 11 alien species were detected while 36 taxa are new or confirmed for the regional floras of Basilicata and/or Campania. In particular 12 taxa are new for Basilicata while four are confirmed. Regarding Campania 14 taxa resulted new for the regional flora and five were confirmed.

The census of the loci classici of 1,400 Italian endemic vascular plants (i.e. not thriving elsewhere with the exception of Corsica and Malta) is here presented and described. The effective place of publication of accepted names, basionyms and homotypic synonyms were identified and critically verified. This often resulted in some change in authorship attribution and, in seven cases, in validation problems ( Asperula cynanchica var. lactea var. nov., A. lactea comb. nov., Biscutella laevigata subsp. raffaelliana subsp. nov., Ferulago nodosa subsp. geniculata comb. & stat. nov., Limonium tineoi comb. nov., L. usticanum sp. nov., Noccaea torreana comb. nov.). The geographic information on the loci classici was excerpted from the protologues, as well as information on typification for the taxa described before 1 January 1958. The names without holotype are 796. For 347 names a lecto- or neo-typification is available in literature, while 449 currently accepted taxa still need of type designation.