A synopsis of Lichenostigma subgen. Lichenogramma (Arthoniales), with a key to the species

A synopsis of the subgenus of lichenicolous fungi Lichenogramma is presented. It comprises eight species of Lichenostigma with oval to elongate ascomata connected to superficial strands of vegetative hyphae. Five of them are described here as new: Lichenostigma diploiciae (on Diploicia subcanescens); L. epipolina (on Diplotomma epipolium); L. gracilis (on Acarospora fuscata); L. rouxii (on Squamarina spp.); and L. subradians (on Acarospora spp., mainly subgen. Acarospora). The concept of the genus Lichenostigma is enlarged to accommodate also species with submuriform ascospores. A key to all the species of the subgenus is provided.