Plectocarpon diedertzianum Y.Joshi, Upadhyay & Chandra was described from India from four different parmelioid host genera. The figure illustrating the holotype specimen in the original publication appears to represent heterogeneous elements. Therefore, a re-examination of the holotype specimen was performed and confirmed the presence of two similar but distinct arthonialean lichenicolous species belonging to Opegrapha melanospila on Parmotrema reticulatum and to a Plectocarpon species on Myelochroa aurulenta. As a consequence, the name P. diedertzianum is lectotypified on the lichenicolous fungus growing on Myelochroa.