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.

植物物种的保护状况是对其进行有效保护的重要工具，但是迄今为止，仅在很少的分类单元中对其进行了评估。在此框架中，此处提供了中欧-南西伯利亚湿草甸物种Juncus atratus Krock。的国家评估。阿特拉图斯是中欧的一种稀有濒危物种，在以前唯一已知的意大利地区被列为区域灭绝物种。该物种最近在意大利的另一个地区（翁布里亚地区卡斯泰尔·玛丽亚平原）重新发现，这是目前唯一确认的国家级已知物种。介绍了其生态和分布特征的概述，同时考虑了书目来源和新数据，包括研究区域的植物社会学背景。根据IUCN标准，该物种在此归为极度濒危（CR）类别。Atratus案 这是在物种分布知识不完整时难以提供详尽而可靠的灭绝风险评估的一个典型例子。