Abstract
A new species of Frullania (subg. Diastaloba) from Southeastern Brazil is described and illustrated. It is characterized by relatively large size, large rounded underleaves with deeply arched insertion line and especially by the narrow, long-cylindrical and falcate lobules with a length-width ratio of 5.5–7:1. The occurrence of Frullania lindenbergii in the Neotropics is rejected. An updated key to the Brazilian species traditionally assigned to F. subgenus Diastaloba is provided.