Graphis tetralocularis, a new lichen with four-celled ascospores from tropical Africa

Abstract

Graphis tetralocularis C. Bock & Hauck is described as a new species from Rwanda. It is characterized by triseptate, hyaline ascospores 12–15(–17)×5–7·5 μm, a connivent, laterally carbonized exciple and by the presence of atranorin. So far, G. tetralocularis is only known from the type locality in central Africa, where it grows epiphytically on Nuxia floribunda in a dry forest.