As a part of a wider study on the diversity of lichenicolous
fungi (Fleischhacker et al. 2015), two taxa, the coelomycete
Lichenodiplis lecanorae (Fig 1AeD) and the ascomycete Muellerella
atricola (Fig 1EeI), gained our interest as they co-occurred multiple
times on thalli of the host lichen Tephromela atra (Fig 1J). A
further screen of herbarium collections revealed the copresence
of Lichenodiplis and Muellerella species also on other lichen
hosts (Fig 1KeM). Lichenodiplis (Fig 1AeD) is the genus introduced
by Hawksworth & Dyko (1979) to circumscribe
species with dark-brown, 1-septate conidiospores with apex
obtuse and base truncated. The genus currently includes 12
species (MycoBank April 2015) that are lichenicolous on different
hosts. These fungi usually invade the apothecia of the hosts,
but they can also produce pycnidia on the thalli if the apothecia
are already heavily infected (Hawksworth & Dyko 1979).