Screening of the essential oil of Thapsia garganica subsp. messanensis (Guss.) Brullo & al., an endemic plant of Sicily (Italy).

The genus Thapsia L., belonging to the Scandiceae tribe of the Apiaceae family, is mainly distributed in the Mediterranean area, North Africa, and the Iberian Peninsula. The use of plants of this genus in popular medicine dates back to the age of ancient Greeks. In the present study the chemical composition of the essential oil from aerial parts of Thapsia garganica subsp. messanensis (Guss.) Brullo & al., an endemic plant of Sicily, never previously investigated, was evaluated by GC-MS. The main components of its essential oil (Tgm) were 1,4-dimethylazulene (17.0%), chamazulene (10.1%), 3-methyl nonane (7.0%), and butyl heptanoate (4.6%). The comparison with all the other studied essential oils of the genus Thapsia is discussed.

New Alien Plant Taxa for Italy and Europe: An Update.

Despite the wide amount of scientific contributions published on alien plant species, their diffusion dynamics, and their interactions with native taxa, it is increasingly difficult to slow down their spreading and their negative impact on habitats. Last recent years, in fact, a sharp rise in the number of new alien plant taxa introduced in Italy and Europe has been recorded. The aim of this work is to investigate most of the Italian territory in order to verify whether this alarming trend is still underway. Specimen collections and/or observations of alien plants have been performed in as many as 12 Italian regions. All the collected specimens are stored in public or private herbaria. Taxa have been identified according to the literature from the countries of origin of the investigated taxa, while the nomenclature followed the current international references. Updates on 106 taxa are reported. In particular, among 117 new records, 89 are first records, 27 are changes to status and there is 1 extinction. Seven new taxa for Italian alien flora are reported, two of which are new to Europe. The administrative regions with the highest number of records are Calabria (48), Sardegna (17) and Sicilia (15). Five of the surveyed taxa, for the first time, have been considered invasive aliens to Italian territory. The unfrequent amount of original results provided by this work, over the simple importance of data itself, proves how floristic investigation, still today, represents one of the most effective tools in broadening the current knowledge about alien taxa and their dynamics.

Delaying drought-driven leaf cell damage may be the key trait of invasive trees ensuring their success in the Mediterranean basin.

Invasive alien species (IAS) threaten the biodiversity richness of the Mediterranean basin, a drought-prone region. However, our knowledge on the adaptive strategies of IAS for facing Mediterranean drought summers is still incomplete. The aim of the present study is to compare the water relations and the critical relative water content (RWC) values leading to loss of cell rehydration capacity of two Mediterranean basin IAS (i.e., Ailanthus altissima (Mill.) Swingle and Robinia pseudoacacia L.) versus two co-occurring native species (i.e., Fraxinus ornus L. and Quercus pubescens Willd.). Study IAS showed higher values of water potential at turgor loss point and osmotic potential at full turgor, lower values of modulus of elasticity and leaf mass area but higher photosynthesis rate, even during the summer, with respect to the Mediterranean native species. These findings supported the hypothesis that IAS are characterized by a resource acquisitive strategy coupled with a safety-efficiency trade-off, compared with Mediterranean native species. However, similar leaf RWC thresholds leading to loss of cell rehydration capacity were recorded in the two groups of species. Moreover, IAS showed higher saturated water content and capacitance values compared with the co-occurring species. Overall, our results suggest that the success of Mediterranean IAS is driven by their ability to delay dehydration damage of mesophyll cells during Mediterranean summer drought, thereby supporting their distinctive high carbon assimilation rate.

The chemical composition of the aerial parts essential oil of Pulicaria odora (L.) Rchb. growing in Sicily (Italy).

The genus Pulicaria Gaertn. (Asteraceae) comprises more than ninety-two species as annual or perennial herbs or small shrubs, distributed in Africa, Europe, and Asia, and concentrated mainly in the Mediterranean region. Several species have been used in the traditional medicine of many countries. In the present study the chemical composition of the essential oil from aerial parts of Pulicaria odora (L.) Rchb., present in the Mediterranean region and collected in Sicily, was analysed by GC-MS. No papers have been previously published on the essential oil of the aerial part of this species. The result showed the presence of large quantity of carbonyl compounds (25.29%), oxygenated sesquiterpenes (23.28%) and thymol derivatives (16.76%). Chemical considerations with respect of other oils of Pulicaria taxa were carried out.

Taxonomic and ecological remarks on Solenopsisbivonae species complex (Campanulaceae).

The populations usually attributed to Solenopsisbivonae (Tineo) M.B.Crespo, Serra & A.Juan are investigated from a taxonomical and morphological viewpoint. Within this species complex, four new subspecies occurring in Sicily and Calabria are recognized, such as subsp. bivonae, subsp. madoniarum, subsp. peloritana and subsp. brutia. In addition, a new species from Cyprus described as S.meikleana and S.bacchettae from Sardinia must be included in this group. The synonymy, typification, description, seed testa morphology, chorology, ecology, illustrations, conservation status, and examined specimens for each taxon are provided. Besides, the analytical keys, distribution maps, and phytosociological arrangement regarding these taxa are given too.