A lichenicolous fungus forming large black, vertically elongate, campylidia-like conidiomata on the thallus of Ochrolechia was recently collected in Austria, Mexico and the USA. The conidia are so remarkable in being multiappendiculate that initially no existing fungal genera appeared to be suitable for its description. Nevertheless, molecular phylogenetic analyses of nuITS and nuLSU sequences recovered the species within the genus Mycocalicium. To date, no species of Mycocaliciales has been reported producing appendiculate conidia. The species is described as new as M. campylidiophorum. The new species was also discovered in the type specimen of Opegrapha chionographa that was collected in Colombia 163 years ago. This discovery led us to revise O. chionographa, originally described as a lichen, and clarify that in fact the name applies to a lichenicolous fungus based on type material that is an admixture of M. campylidiophorum, an Ochrolechia and an Opegrapha species. The name is shown to apply to the Opegrapha species and lectotypified as such. Opegrapha blakii is treated as synonym of O. chionographa. Key words: Arthoniales, fungi, Mycocaliciales, Opegrapha, phylogeny, taxonomy.