Phylogenetic placement of Leptosphaeria polylepidis, a pathogen of Andean endemic Polylepis tarapacana, and its newly discovered mycoparasite Sajamaea mycophila gen. et sp. nov.

Polylepis tarapacana forms one of the highest-altitude woodlands worldwide. Its populations are experiencing a decline due to unsustainable land-use practices, climate change, and fungal infection. In Sajama National Park in Bolivia, Polylepis tarapacana is affected by a disease caused by the pleosporalean fungus Leptosphaeria polylepidis, recently described in 2005. In this study, the integrative morphological and molecular analyses using sequences from multiple DNA loci showed that it belongs to the genus Paraleptosphaeria (Leptosphaeriaceae, Pleosporales). Accordingly, the appropriate new combination, Paraleptosphaeria polylepidis, is made. Pseudothecia of Pa. polylepidis were found to be overgrown by enigmatic conidiomata that were not reported in the original description of this fungus. Morphological and molecular analyses using sequences from two DNA loci revealed that they belong to an undescribed genus and species in the family Dictyosporiaceae (Pleosporales). The new generic and specific names, Sajamaea and S. mycophila, are introduced for this unusual fungus.