The Vegetation Prodrome of Italy was promoted in 2012 by the Italian "Ministry of Environment, Land and Sea Protection", in collaboration with the "Italian Society of Botany", to provide a comprehensive and systematic catalogue and description of Italian plant communities. The Prodrome that is presented in this paper is the first full organic synthesis of the vegetation of Italy at the alliance syntaxonomic level. It fulfils several needs, the main one being a unified and comprehensive national framework that may make an important contribution to the definition of the European Vegetation Prodrome. Syntaxonomy, as well as taxonomy, is sometimes based on considerations that may in part diverge: several authors tend to favour models that are divisive or aggregative to a greater or lesser extent in terms of flora, biogeography and ecology. These different points of view stimulate the scientific debate and allow the adoption of a framework that is more widely supported. The Prodrome includes 75 classes, 2 subclasses, 175 orders, 6 suborders and 393 alliances. The classes were grouped into nine broad categories according to structural, physiognomic and synecological elements rather than to syntaxonomic criteria. The rank, full valid name, any synonymies and incorrect names are provided for each syntaxon. The short declaration highlights the physiognomy, synecology, syndynamics and distribution of the plant communities that belong to the syntaxon. The Prodrome of the Italian Vegetation is linked to the European Strategy for Biodiversity, the European Habitats Directive and the European Working Groups related to the ecosystems and their services. In addition to basic applications, the Prodrome can be used as a framework for scientific research related to the investigation of the relationships between plant communities and the environmental factors that influence their composition and distribution

We drew up a checklist of the Italian vegetation (http://www.prodromo-vegetazione-italia.org/), up to the syntaxonomical rank of alliance. During the compilation of this checklist, we observed that some syntaxa were invalidly published. For this reason, in this article we validated some syntaxa names and, at the same time, described new syntaxa of different hierarchical levels. Therefore, 10 new orders, 1 new suborder, 18 new alliances, 3 new suballiances and 5 new associations are described here. These new syntaxa belong to the following classes: Adiantetea capilli-veneris, Parietarietea judaicae, Thlaspietea rotundifolii, Artemisietea vulgaris, Stellarietea mediae, Galio aparines-Urticetea dioicae, Mulgedio alpini-Aconitetea variegati, Trifolio medii-Geranietea sanguinei, Festuco-Seslerietea, Salicetea herbaceae, Festuco valesiacae-Brometea erecti, Molinio-Arrhenatheretea, Cisto cretici-Micromerietea julianae, Rhamno catharticae-Prunetea spinosae, Salici purpureae-Populetea nigrae, Salicetea purpureae, Quercetea ilicis and Querco roboris-Fagetea sylvaticae

In this contribution new data concerning the distribution of native vascular flora in Italy are presented. It includes new records, exclusions, and confirmations to the Italian administrative regions for taxa in the genera Asplenium, Bolboschoenus, Botrychium, Chamaerops, Crocus, Galeopsis, Grafia, Helosciadium, Hieracium, Juniperus, Leucanthemum, Lolium, Medicago, Phalaris, Piptatherum, Potamogeton, Salicornia, Salvia, Seseli, Silene, Spiraea, Torilis and Vicia. Rhaponticoides calabrica is proposed as synonym novum of R. centaurium. Furthermore, new combinations in the genera Galatella and Lactuca are proposed

online. The Italian Vegetation Prodrome (IVP), implemented on behalf of the Ministry of the Environment and Protection of Land and Sea (also known as MATTM) on the basis of two agreements entrusted to the Italian Botanical Society, has been drawn up to the lower level of suballiance. In the current paper, the syntaxonomical choices adopted in the description and the typification of the new syntaxa are explained through eight main conceptual issues. Among these, there are several Mediterranean and sub-Mediterranean syntaxa, which contribute to improve knowledge of the phytocoenosis biodiversity of these biogeographic areas. Indeed, these Mediterranean and sub-Mediterranean territories are the most important European areas in terms of flora, vegetation and habitats. In the past, the syntaxa of these bioclimatic and phytogeographic areas were mainly included in classes widespread over Europe and in hierarchical levels that are, in our opinion, inappropriate for describing their floristic and phytocoenotic richness. Therefore, we decided, in some cases, to raise their hierarchical level in order to promote a better and more appropriate syntaxonomical classification. The definition of such syntaxa is the result of a research carried out on various aspects of the flora, ecology and dynamic features of the plant communities; they have often considered large geographical territories, wider than Italy and, sometimes, even Europe. The case study of some syntaxa belonging to the classes Euphorbio paraliae-Ammophiletea australis, Sarcocornietea fruticosae, Festuco valesiacae-Brometea erecti, Trifolio medii-Geranietea sanguinei, Rhamno catharticae-Prunetea spinosae are shown.

In the course of the project "Syntaxonomic checklist of the Italian classes, orders and alliances (Vegetation Prodrome of Italy)", promoted in 2012 by the Italian "Ministry of Environment, Land and Sea Protection" in collaboration with the "Italian Society of Botany", it arises that some syntaxa are not validly published according to the International Code of Phytosociological Nomenclature rules. For this reason, these syntaxa names are validated in this paper. Furthermore, other new syntaxa of different hierarchical levels are here described for the first time. Therefore, one new order, two new suborders, six new alliances, two new suballiances and three new associations are here described. These new syntaxa belong to the following classes: Juncetea maritimi, Stellarietea mediae, Trifolio medii -Geranietea sanguinei, Alnetea glutinosae and Salici purpureae -Populetea nigrae. Finally, the syntaxonomic arrangement of Alnion incanae is here discussed.