Studies in Microglossum viride (Pers.) Gillet revealed that the name was used incorrectly for two similar but different taxa. Analyses of morphological, ecological and molecular (sequences of ITS and LSU region of rRNA gene) characters of type and voucher specimens of M. viride and related taxa resulted in delimitation and description of a new species, Microglossum griseoviride V. Kučera, Lizoň & M. Tomšovský. Lectotypes of Geoglossum viride Pers., and epitype of Geoglossum viride are designated. Species Microglossum minus Velen. and Microglossum lutescens Boud. are confirmed to be conspecific to M. viride.
Keywords: Geoglossaceae; ITS; LSU; morphometrics; taxonomy.