New additions to the vascular flora of the Kastellorizo island group (East Aegean Islands, Greece)

This work is a contribution to the knowledge of the vascular flora of the archipelago (SE Greece), which is part of the South Anatolian biogeographical province. An autumn survey (October 2025) identified nine species new for the archipelago ( Amaranthus viridis , Dittrichia graveolens , Eclipta prostrata , Euphorbia prostrata , Gastridium phleoides , Orobanche minor , Portulaca oleracea , Setaria adhaerens , Sorghum halepense ) and clarified the distribution of several taxa of great biogeographical interest (e.g. Campanula kastellorizana , Colchicum macrophyllum , Cyclamen maritimum , Dianthus muglensis , Polygonum praelongum , Thliphthisa brevifolia ). A checklist is also presented for Aghios Georgios, a small satellite islet (1 ha) with a high species richness as 149 plant taxa have been recorded in total. The Kastellorizo archipelago, rich in about twenty endemic vascular plants, is a very interesting biogeographical entity that deserves increased protection of its biodiversity.