Mariacristina Villani

Inventory of the non‐native flora of Italy

Abstract In this paper we present a comprehensive inventory of the non‐native vascular flora of Italy, which was produced within the project “A survey of the Italian non‐native flora”, funded by the Italian Ministry for the Environment. Previously published floristic accounts were the main source of information. Historical records were critically revised and integrated with recent literature, data from herbaria and some unpublished information, so as to obtain a complete, up‐to‐date catalogue of the non‐native vascular plant species that occur spontaneously in Italy. The inventory lists 1023 non‐native species and subspecies, which account for 13.4% of all the Italian flora. The Italian non‐native flora was divided, according to its residence time, into 103 archaeophytes and 920 neophytes. According to its current invasion status, it was classified into 437 casual (42.7% of all non‐native) and 524 established taxa, the latter being divided into 361 naturalized non‐invasive (35.3%) and 163 invasive taxa (15.9%). The inventory includes a group of 62 species (6.1%) that lack recent records (i.e. since 1950). By combining local expertise into a unified, nationwide scheme using a standardized method and terminology, the inventory provides the essential scientific basis for the development of plant invasion research and management in the country.

Non‐native flora of Italy: Species distribution and threats

Abstract In this paper, we provide an overview of the distribution and invasive status of non‐native species in the Italian flora across its administrative regions, biogeographic regions and main land use types, and a synthesis of current knowledge on the threats they pose within the country. The information on non‐native plant species collected during the project “A survey of the non‐native Italian flora” was used to compile comprehensive regional and national databases. The number of non‐native species within a given administrative region increases in proportion to its size, resident population density and latitude, reaching the highest values in the intensively cultivated, heavily industrialized and urbanized Po Plain in northern Italy. The number of casual species is positively correlated with the number of yearly visitors in each region and negatively correlated with the proportion of mountainous terrain within the region. If compared with the Continental and Mediterranean biogeographic regions, the Alpine region yields the lowest number of non‐native species and lowest proportion of casual species. The number and density of introduced species is highest in artificial land use types, particularly in urban areas. A negative impact is reported to be exerted by 203 species, most of which are agricultural weeds.

Fungi associated with the southern Eurasian orchid Spiranthes spiralis (L.) Chevall

The hitherto unknown relationships between the European orchid Spiranthes spiralis (L.) Chevall and its internally associated fungi were explored by a combined approach involving microscopy-based investigations at a morpho-histological level as well as by molecular analyses of the identity of the eukaryotic endophytes present in the root tissue of the plant. We found that this orchid which is currently reported to have a vulnerable status in northern Italy, can host and interact with at least nine types of fungi. Some of these fungi show similarity to mycorrhizal genera found in orchids such as the Ceratobasidium-Rhizoctonia group. Other fungi found are from the genera Davidiella (Ascomycota), Leptosphaeria (Ascomycota), Alternaria (Ascomycota), and Malassezia (Basidiomycota), some of which until have not previously been reported to have an endophytic relationship with plants. The repeated occurrence of often pathogenic fungi such as Fusarium oxysporum, Bionectria ochroleuca, and Alternaria sp., within healthy specimens of this orchid suggests a tempered interaction with species that are sometimes deleterious to non-orchid plants. The fact is reminiscent of the symbiotic compromise established by orchids with fungi of the rhizoctonia group.

Statistical and ecological analysis for the evaluation of floristic diversity: The case of a volcanic complex in North-eastern Italy (Colli Euganei, Padova, Italy)

ABSTRACT The Euganean Hills are a volcanic mountainous complex, which rises from the eastern Po Plain, and consists of about one hundred hills, rising from 80 m to 604 m above sea level. In the studied area, 1158 taxa of Tracheophytes have been collected. The chorological and life-form analyses of this flora have shown the predominance of the Mediterranean s.l. elements and of the hemicryptophytes, followed by the therophytes. The chorological aspect of this floristic complex was analysed. A cross-spectrum was calculated to see how life-forms are represented in the different chorotypes. A comparison with the biological and chorological spectra of the Veneto Region and of Italy as a whole was also carried out. Several species of remarkable floristic and phytogeographical interest have been found, as well as some included in the national and Regional lists of protected species.

Identification of the root nodule symbiont of the rare legume species Hedysarum confertum Desf. (Hedysarum humile L.) in its Italian relictual site

Abstract Hedysarum confertum Desf. (Fabaceae) represents a particular rarity in the Italian flora, signalled as late as in 1931 and nowadays still occurring only in few isolated stations in the central Apennine mountains. Within a framework of loss prevention of relevant botanical resources and landscape protection, we aimed at investigating possible factors limiting the distribution of this taxon and its potential to colonize suitable habitats. For these reasons we verified the existence of symbiotic relationships between H. confertum and soil bacteria assessing their identity and physiology. The plant was found to form histologically complete root nodules which are regularly invaded by bacteria. However, bacterial isolation in pure culture and cultivation ex planta appears prevented by a state of non-culturability. To assess the taxonomical position of nodule occupants the problem was circumvented by direct PCR amplification of 16S ribosomal RNA gene and nucleotide sequencing which revealed that H. confertum hosts bacteria of the genus Mesorhizobium, and that their ribosomal sequence has undergone a higher-than-average degree of divergence from the mesorhizobia nodulating other legumes in different countries. These differences suggest a possible link between the non-culturability of the symbiont and the isolated relictual status of its host plant.

The genus Callitriche in northeastern Italy: First systematic contribution

The aim of this paper is a better understanding of the distribution and taxonomy of the species of the genus Callitriche L. in northeastern Italy. In our country, only a few studies dealing with this topic have been carried out. The taxa have been collected in the neighborhood of Padua and Treviso (Veneto Region) and studied from karyological, micromorphological (LM and SEM), macromorphological, and statistical points of view. The specimens are situated in the Herbarium of Padua University (PAD). Knowledge about the distribution area of C. obtusangula has been widened; the presence in Italy of C. platycarpa has been confirmed and a hybrid collected. On the basis of karyological and morphological data and their statistical analysis, the hybrid could be a cross between C. obtusangula and C. stagnalis.

A morphological, caryological and morphometrical analysis of Teucrium euganeum Vis. and its allies

The aim of the present study is to clarify the taxonomic position of Teucrium euganeum Vis. vis à vis T.siculum (Rafin.) Guss. and T.scorodonia L. The study is based on an analysis of macro- and micro-morphological characters, type, and distribution of trichomes in different parts of the plant, chromosome counts, and a statistical analysis of such morphometric data. The results of the study allow one to consider the populations of the Euganean Hills (Padua, north-eastern Italy) as a sub-species of T.siculum, and, therefore, a new combination is proposed: Teucrium siculum (Rafin.) Guss. subsp. euganeum (Vis.) Tornadore, comb. et stat.nov.