Chasmophytic vegetation of the class Asplenietea trichomanis in south-eastern Italy

The southeast of Italy is characterized by the presence of some highly phytogeographically relevant taxa with a Balkan-Aegean distribution. Three of these taxa, Campanula versicolor, Carum multiflorum and Scrophularia lucida, characterize the chasmophytic vegetation in central-southern Apulia (Serre Salentine and Bassa Murgia). Chasmophytic vegetation has already been referred to the Onosmetalia frutescentis order and to its only alliance Campanulion versicoloris, which are syntaxa with mainly a south-western Balkan distribution. This paper reports a phytosociological study of chasmophytic vegetation throughout the entire distributional range of these three species in south-eastern Italy and describes two new associations: Piptathero holciformis-Campanuletum versicoloris and Iberido carnosae-Athamantetum siculi.We analyse their floristic relationships with other communities described for southern Italy, the Adriatic area and the southern Balkans. As distinct from reports in the literature, the results show that south-eastern Italian rupicolous communities, now grouped under the new alliance Caro multiflori-Aurinion megalocarpae, have higher floristic similarity with the order Asplenietalia glandulosi, where they have been placed. In other words, the presence of different species gravitating in the East discriminates the chasmophytic vegetation of south-eastern Italy within a central Mediterranean order, rather than justifying its assignment to Onosmetalia frutescentis, whose distributional area is limited to the Balkan Peninsula.