An updated inventory of the vascular flora alien to Italy, providing details on the occurrence at regional level, is presented. The checklist includes 1597 species, subspecies, and hybrids, distributed in 725 genera and 152 families; 2 taxa are lycophytes, 11 ferns and fern allies, 33 gymnosperms, and 1551 angiosperms. 157 taxa are archaeophytes and 1440 neophytes. The alien taxa currently established in Italy are 791 (570 naturalized and 221 invasive), while 705 taxa are casual aliens, 4 are not assessed, 7 are of unknown regional distribution, 47 have not been confirmed in recent times, 3 are considered extinct or possibly extinct in the country, and 40 are doubtfully occurring in Italy. This checklist allows to establish an up-to-date number (9792) of taxa constituting the whole (native and alien) Italian flora.

We present the first inventory of the segetal flora of Italian winter cereal crops and allied crop types. The database consists of over 30,000 records, derived from different sources. We provide information and analyses on life forms, chorotypes, Ellenberg indicator values and preferential habitats of the flora. The inventory includes 987 vascular taxa and nothotaxa (868 species, 118 subspecies and 1 nothosubspecies), belonging to 354 genera and 55 families. Characteristic segetal species are 128, while 740 are generalist or accidental species from other habitats. Species exclusive of segetal habitats are 47. One species is extinct, and one is not confirmed in Italy. We recorded 42 neophytes, 15 archaeophytes and 10 cryptogenic species. Segetal species that are threatened in Europe are 45. Species in the Italian Red List are four, and five are threatened endemic species. The most frequent species are Papaver rhoeas (1,045 records), Convolvulus arvensis (623) and Ranunculus arvensis (571). Most species are therophytes (64%) and have a Mediterranean (36%), wide (14%) or eastern (13%) distribution range. Mean Ellenberg indicator values revealed relevant ecological affinities between the inventoried flora and cultivated winter cereals. Our work represents the basis for future applied studies in botany, ecology and agronomy.

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.

European wild carnations (Dianthus) are represented by a high number of taxa organized in unresolved taxonomies. In particular, taxa belonging to the Dianthus virgineus L. complex in the Central Mediterranean have been delimited mainly with qualitative morphological data and still await quantitative investigations, which are vital to understand boundaries and relations among plant diversity groups. Here, we examine the phenotypic features of nuclear genome organization testing for species boundaries in this complex. We have studied the chromosome number, the total haploid length (THL), and the relative genome size (RGS) in 122 populations belonging to 25 out of 33 taxa of the complex. All the studied populations have 2n = 2x = 30 chromosomes, and the THL ranges from 14.09 to 20.71 μm. Genome size estimations support the absence of polyploidization events, but show a certain degree of variation (0.318–0.423 arbitrary units). The RGS variation is not in agreement with current taxonomic treatment, but rather shows a geographical pattern, with higher values in Sicily and Sardinia. No correlation between the THL and the RGS was detected, possibly due to the stable chromosome number and the small size of chromosomes. A number of evolutionary unique groups lower than the number of currently accepted taxa may be hypothesized.