Taxonomical and chorological study on the central Mediterranean Basin endemic Arenaria bertolonii Fiori & Paol. (Caryophyllaceae)

Arenaria bertolonii Fiori & Paol. is an orophyte and endemic European species of Italy and France. The name Stellaria saxifraga Bertol. (basionym of A. bertolonii) is typified on a herbarium specimen kept in BOLO. Infraspecific variability of the species is discussed and a comparison with related taxa included in the Subg. Arenaria was made on the basis of morphological analyses and chorological and cytological data. At the sectional level, the results show that A. bertolonii is clearly separate from the morphological and chorological points of view, thus supporting the proposal for a new monotypic section (Sect. Italiae Iamonico) of central Mediterranean species. The analysis of infraspecific variability instead highlighted overlapping morphological characteristics; the distribution areas of the infraspecific taxa are sympatric and any cytological difference is lacking, thus pointing to a synonymization of the names. Notes on the ecology and distribution of A. bertolonii are also provided.