Abstract
Thymus apulus, a new species from the calcareous highland (Murge hill area) of Apulia and Basilicata, southern Italy, is described and illustrated. The new species belongs to Thymus sect. Hyphodromi, and has been confused in the past with T. striatus (a southeastern European species), or T. spinulosus (a species strictly endemic to central and southern Italy). A morphometric analysis to assess the taxonomic relationships of the putative new species and the closely related T. spinulosus and T. striatus was carried out. Multivariate and univariate morphometric analyses demonstrate that T. apulus is clearly different from T. striatus and T. spinulosus. It can be reliably identified by a combination of quantitative and qualitative diagnostic characters, including pink corolla, capituliform to elongate inflorescence, predominantly glabrous leaves with rare sessile oil glands and non-parallel lateral veins, and distinct morphometric traits of the bracts and calyx. The distribution of T. apulus is restricted to several localities in the Murge highland (Apulia and Basilicata), within Alta Murgia National Park (SCI IT9120007 "Alta Murgia") and Murgia Materana Park (SCI IT9220135 "Gravine di Matera"). Thymus apulus usually grows in sub-Mediterranean xeric grasslands corresponding to habitat 62A0, "Eastern sub-Mediterranean dry grasslands (Scorzoneratalia villosae)", included in Annex I of the Habitats Directive (92/43/EEC). Furthermore, the conservation status assessment of the new species, according to IUCN categories and criteria, is proposed and discussed, and an analytical key for dried herbarium specimens to the species of T. sect. Hyphodromi in Italy is presented.