Bryum minii Podp. ex Machado-Guim. is a rare western-Europe endemic that is here reported for the first time for south-central Spain in the Iberian Peninsula. This new locality links the previously widely disjunct localities from France and Sardinia with the core of its distribution in Portugal; most of the intervening area is of calcareous nature, inappropriate for this acidophilous species. A detailed description, diagnostic characters with photographs, and a map of the currently known distribution are provided. We also discuss the correct authorship as the name must be attributed to A. Machado-Guimaraes, the Portuguese bryologist. Bryum minii var. brevifolium Machado-Guim. is lectotypified and the name is here considered synonymous with B. minii. The species seems related to the taxa now included in the genera Rosulabryum Spence or Plagiobryum Lindb., depending on the taxonomic concept employed.