Zwackhiomyces cervinae , a new lichenicolous fungus ( Xanthopyreniaceae ) on Acarospora , with a key to the known species of the genus

Zwackhiomyces cervinae Calat., Triebel & Perez-Ortega is described as new to science from Spain and Iran. This lichenicolous species grows on the lateral side of the squamules of Acarospora cervina , and it is characterized by its relatively large ascospores, which are brown when overmature. It is compared with several Zwackhiomyces species and with other taxa sharing some of its characters. A key to all the known species of the genus is also provided.