We report Eryngium absconditum, a new species from Cordillera de Amambay, an area that belongs to the biodiversity hotspot of the Cerrado in Paraguay. The species was collected more than a century ago, but the collections remained unnoticed and misidentified until now. We describe, illustrate, and provide information on the geographical distribution and habitat of the new species. We also analyze and illustrate the morphological characteristics that differentiate it from Eryngium rojasii and E. paraguariense, the most similar species to the new. This study highlights the importance of Amambay as an area rich in endemic plant species and the need for continued taxonomic studies and the establishment of regional conservation policies for this region with its biodiversity under threat.