Thymus paronychioides (Lamiaceae), a Neglected Species from Sicily Belonging to Thymus sect. Hypodromi

摘要

The taxonomic position of Thymus paronychioides Celak., a neglected species until recently treated as a synonym of Th. striatus or Th. spinulosus, is reviewed. Karyological and morphological characters were used for comparative analyses with closely related taxa belonging to Th. sect. Hypodromi, such as Th. striatus and Th. spinulosus, occurring in the Mediterranean area (Italy, Balkans and Turkey). Multivariate and univariate morphometric analyses showed that Th. paronychioides is clearly distinct from Th. striatus and Th. spinulosus in the unique features of leaves (elliptical-spathulate, fleshy, with ± curved and prominent lateral veins), in the inflorescence being always capitate with few flowers, and in the larger corolla with the tube usuallyexceeding the calyx. Furthermore, chromosome counts showed that Th. paronychioides is polyploid (In = ca. 60), whereas 77;. spinulosus and 777. striatus are diploid (2n = 2x= 26). Hence, Th. paronychioides is shown to be an independent taxon, endemic toNW Sicily, placed within Th. sect. Hypodromi subsect. Serpyllastrum. Finally, an identification key to the Italian species of Th. sect. Hypodromi is provided.