Aptroot, A.,Yazici, K. & Košuthová, A. 2015. Three Placynthiaceae reported new to Asia from limestone in Turkey, with the description of the apothecia of Placynthium posterulum. — Herzogia 28: 288–292.
Collolechia caesia, Placynthium hungaricum, and P. posterulum are reported for the first time from Asia from limestone outcrops in Turkey. The apothecia of Placynthium posterulum, which were so far unknown, are described: They have a thalline margin, a character that within the genus is only shared with P. stenophyllum.