Karyology, chorology and bioecology of the genus Limonium (Plumbaginaceae) in Sardinia

Abstract The genus Limonium is very differentiated in Sardinia. Thirty‐eight prevalently endemic (76%) species are known at present. Most of them (21 species) are triploid with a basic number x = 9; some species are widely distributed and, because of their scarce morphological affinities, presumably ancient; others have a more or less restricted distribution area, are weakly differentiated and probably of recent origin. There is also a diploid group with 2n = 18, which occurs in coastal areas, represented generally by obliged allogamous species (14) with an incompatible pollen/stigma heteromorphic system sometimes associated with heterostyly. The diploids have developed coastal belt vicariant species, territorially associated with the system of triploids. Part of the triploids of recent origin is clearly derived from a process of allotriploidy, i.e. hybridisation between a diploid and a triploid living next to each other. In Corsica and Sardinia, due to scarcity of tetraploids, the genus Limonium is chara...