The vascular flora of the Apuan Alps (Tuscany, Central Italy)

We present an updated and critically revised list of the vascular flora occurring in the Apuan Alps (Tuscany), a renowned area of high naturalistic interest. The list is based on a literature survey, herbarium and field studies. The Apuan Alps host an established flora of 1,987 specific and subspecific taxa (including 106 naturalized and 24 invasive aliens), 76 casual aliens and 27 hybrid taxa. Three taxa are new for Tuscany: Anthyllis vulneraria subsp. pulchella, Chaenomeles speciosa (casual alien), and Thalictrum minus subsp. saxatile, while Helianthemum oelandicum subsp. alpestre is excluded from the regional flora; 47 taxa are new for the study area (31 native, 16 alien). Concerning old records, 168 (158 native, four hybrid, and six casual alien taxa) were not confirmed, albeit considered reliable. Moreover, we considered 10 taxa as locally extinct, 44 as doubtfully occurring, and 14 as reported by error. Life forms suggest a transitional situation between a Mediterranean bioclimatic context and a more distinctly subcontinental one. Regarding the chorological spectrum, there is a clear prevalence of species with a distribution centered in the Eurosiberian Region, with a biogeographically relevant component represented by 152 taxa, among which 93 Italian endemics (30 of them narrowly endemic to Apuan Alps). Based on species-area relationship, the number of native taxa exceeds the one expected, while the number of alien taxa is lower than expected. This positions the area as objectively rich in terms of its flora and of high natural value.