Jabłońska, A. 2010. The lichen genus Porpidia in Poland III. — Herzogia 23: 217–228.
The taxonomy, chemistry, morphology, habitat requirements and distribution of Porpidia flavocruenta, P. grisea, P. macrocarpa, P. P. nigrocruenta, P. speirea and P. zeoroides from Poland are detailed. Porpidia flavocruenta is recorded for the first time for Poland and P. nigrocruenta is new to Ukraine. Porpidia nigrocruenta is considered to be a distinct species. The occurrence of P. flavicunda, P. hydrophila and P. trullisata has not been confirmed during the study in Poland and the status of these taxa remains unknown. A key for taxa in Poland, including those with unconfirmed occurrence in the country, is provided.