Abstract
Schlotheimia spinomitria (Orthotrichaceae, subg. Schlotheimia), is proposed, described and illustrated as a new species based on collections from central Brazil. It is characterized by its distinctive calyptra ornamentated with multicelled foliose spines. S. spinomitria is currently known only from three specimens from the Cerrado (Savana) area, and could be considered rare, vulnerable and potentially threatened. A key is provided to distinguish it from the other Brazilian species with ornamented calyptra.