First record of Scorzoneroides muelleri (Asteraceae) in Apulia: phytosociological analysis and conservation status in Italy

Scorzoneroides muelleri (Sch. Bip.) Greuter & Talavera (Asteraceae), a very rare species, is a hygrophyte occurring in the southern part of the Mediterranean basin. In Italy, the presence of this species is confirmed for Sicily, while in Sardinia and Liguria it has not been recorded any longer. Three new localities, recently found in Apulia (southern Italy), are here reported. The floristic composition of Scorzoneroides muelleri communities in Italy is here analyzed, in order to characterize the diversity of populations in relation to different ecological conditions and assess their conservation status at regional level. A total of 70 plots were surveyed. For each plot, the floristic composition and cover of the species were determined using standard method of releves. Cluster analysis and Principal Components Analysis (PCA) allowed the identification of three vegetation types which correlated with ecological gradients ranging from the coast to inland areas. The first is characterized by the presence of Lythrum hyssopifolia (coastal zone, Sicily), the second by the presence of Trisetaria aurea (inland zone, Sicily) and the third by Sphenopus divaricatus (coastal zone, Apulia). The limited distribution of this taxon is a probably a consequence of the degradation, fragmentation and reduction of its natural habitat.