Research on the genus Limonium (Plumbaginaceae) in the Tuscan Archipelago (Italy)

Abstract

Summary Morphological and karyological analyses were carried out. Chromosome numbers were determined (when lacking) and chromosome measurements were studied statistically. A different interpretation of the ‘stem’ is proposed. Results obtained and the obvious geographical isolation preventing gene exchange between populations, depict a case of slow divergent speciation of caryologically rather homogeneous populations where heterostyly plays a significant role. Therefore the author is of the opinion that each island hosts a different, though little differentiated species. Most of them have already been named [L. ilvae Pignatti (Elba), L. gorgonae Pignatti (Gorgona), L. planesiae Pignatti (Pianosa), L. dianium Pignatti (Giannutri), L. doriae (Sommier) Pignatti (Formiche di Grosseto), L. sommierianum (Fiori) Arrigoni] is typified and its presence limited to the Giglio Island. Two new species are described: Limonium montis-christi Rizzotto and Limonium caprariae Rizzotto. An identification key is proposed.