Contribution to the floristic knowledge of Monte Labbro, Tuscany, Italy

During the years 1991-1993, floristic researches have been carried out in the Monte Labbro area (southern Tuscany, Italy). The study area, about 12.2. Km2 large, is mailny covered by intensively grazed grassland and shrubby-grassland communities. In this paper a check-list of 398 entities, among which 366 are new for the area, was realized. Seven are the species introduced for forestry which were not naturalized. Several of entities found are phytogeographycally interesting, because endemic, rare or with scattered distribution and because raching their distribution area limit. Eleven Italian or regional endemic were recorded, Viola etrusca Erben being the most abundant. It is finally evidenced the need of in depth study aiming to detect the optimal grazing pressure to preserve the high plant diversity.