The distribution of Osmunda regalis L. in Tuscany [Contributo alla conoscenza della distribuzione di Osmunda regalis L. in Toscana]

The results of bibliographic, herbarium and field studies relative to the distribution of Osmunda regalis are reported. The species is distributed in the west of the region in some principal groups (dispersal centres): at the base of the Alpi Apuane, in lower Arno Valley (Padule di Fucecchio-Monte Pisano- San Rossore), in Merse Valley, on Monte Leoni, in the Tuscan Archipelago (Elba and Giglio islands) and in the Argentario area. The distribution of the species is linked to springs swamps, water ways and marshes in a range between 0 and 600 m of altitude. New sites in southern Tuscany have been located through field research, and some old sites have been examined to verify the distribution of the species in recent years. The risk of its extinction in Tuscany is mainly due to degradation and reduction of habitat. Some information about the rarity of the species at a regional level is also provided. © 2018 Società Botanica Italiana onlus.