Abstract
During botanical researches, we found an isolated population of Coriaria myrtifolia for the first time in Tuscany (Italy). This study aims to gain insights into the distribution of this species and its associated vegetation. We studied the scrub vegetation dominated by C. myrtifolia at the currently known southernmost limit of its distribution in Italy through the phytosociological method. We present and discuss the attribution of the Tuscan relevés to the association Rubo ulmifolii-Coriarietum myrtifoliae O. de Bolòs 1954 (Pruno spinosae-Rubion ulmifolii O. de Bolòs 1954), firstly reported for peninsular Italy. Our data allowed us to describe a new subassociation viburnetosum tini differentiated by the Mediterranean shrub Viburnum tinus subsp. tinus and by the meso-xerophilous herbs Lathyrus latifolius and Viola alba subsp. dehnhardtii. This research also suggests that, although vast areas of Tuscany lie in the Temperate submediterranean macrobioclimate, including our study area, the presence of Mediterranean elements in the shrub vegetation can be conspicuous when local factors, such as a water body, mitigate the microclimate.