First records of Calamagrostis purpurea (Poaceae) in the Carpathians, a relict species new to the flora of Slovakia, Ukraine, and Romania

The first records of Calamagrostis purpurea, an apomictic wetland grass species with a Euro-Siberian, predominantly boreal distribution, are reported for the Carpathians. This significantly expands the species' range in Central Europe eastwards from the known localities in Austria and Czechia. Due to in situ finds and revision of the herbarium vouchers, C. purpurea was discovered in the Western Carpathians in Slovakia (the Nizke Tatry Mts) as well as in the Eastern Carpathians in Ukraine (the Chornohora Mts) and Romania (Dorna Depression, the Harghita, Bodoc Mts, Intorsura Buzaului Depression) at 6 sites in total. All these newly found localities are situated within 870-1570 m a.s.l. The locality in the Nizke Tatry Mts is at the highest elevation, while those in the Romanian Carpathians are the southeasternmost in Central Europe. In the Carpathians, C. purpurea is confined to undisturbed wetland habitats, which implies its relict origin in the region. A distribution map, habitat characteristics, morphological description, and images of the plants from the Carpatians are provided. Carpathian populations tested with flow cytometry are DNA-octoploid (the predominant ploidy level of the species in Europe). Because of the species' rarity and vulnerability, it is suggested to include C. purpurea in the next editions of the Red Data Books and/or Red Lists of the corresponding countries.