Juncus atratus Krock. (Juncaceae) rediscovered in Italy: a species deserving urgent conservation actions

Abstract

The conservation status of plant species is an important tool for their effective conservation, but it has been evaluated only in a low number of taxa up to now. In this frame, the national assessment of Juncus atratus Krock., a Central European-South Siberian wet meadow species, is here provided. J. atratus is a rare and threatened species in Central Europe and has been listed as Regionally Extinct in the only Italian Region where it was previously known. The species has recently been rediscovered in Italy, in a different area (Castel S. Maria plain, Umbria Region), and at present, this is the only confirmed known location at national scale. An overview of its ecological and distributive characteristics is presented, considering both bibliographic sources and new data including its phytosociological context in the study area. According to the IUCN Criteria, the species is here ascribed to the category Critically Endangered (CR). The case of J. atratus is an emblematic example of the difficulty of providing exhaustive and reliable extinction risk assessment when knowledge on the species distribution is not complete.