The new genus Brianaria S. Ekman & M. Svensson is introduced for the Micarea sylvicola group, with the new combinations Brianaria bauschiana (Körb.) S. Ekman & M. Svensson, B. lutulata (Nyl.) S. Ekman & M. Svensson, B.sylvicola (Flot. ex Körb.) S. Ekman & M. Svensson and B. tuberculata (Sommerf.) S. Ekman & M. Svensson. The new genus is characterized by a chlorococcoid, non-micareoid photobiont, small, convex apothecia without an excipulum, an ascus of the ‘Psora-type’, 0–1-septate ascospores, dimorphic paraphyses, and immersed pycnidia containing bacilliform conidia. Brianaria is shown to form a monophyletic group in the Psoraceae, where it is probably the sister group to Psora and Protoblastenia.