Abstract
Gloeoheppia is re-established as a separate taxon; the genus differs from Heppia in apothecial development and thallus structure. Gloeoheppia and the related genera Gudelia Henssen and Pseudopeltula Henssen described here are placed in the new family Gloeoheppiaceae in the Lichinales. In habit, the genera of Gloeoheppiaceae resemble species of Heppia and Peltula, whereas in apothecial development they correspond to some extent to the Lichinaceae. The species Gloeoheppia polyspora Henssen, Gloeoheppia rugosa Henssen, Pseudopeltula dicyanophora Henssen, Pseudopeltula heppioides Henssen, Pseudopeltula myriocarpa Henssen and Gudelia mexicana Henssen, are described for the first time. In Gloeoheppiaceae the thalli are ecorticate and the hyphae reticulately branched. The prototunicate asci contain eight, or up to 16, colourless and simple, occasionally two-celled spores. In species of Pseudopeltula, the apothecia are of a complex structure. The cyanobionts are small and single-celled; in P. dicyanophora ‘ internal cephalodia ’ with an additional, filamentous cyanobiont are formed. Lectotypes are designated for Endocarpon turgidum Ach. and Heppia furva Hue in Patouill.