Osyczka, P. 2012. The lichens of Cladonia, ‘supergroup’ Perviae, in Poland. — Herzogia 25: 15 –30.

This study based on the examination of approximately 1400 herbarium specimens from the members of Cladonia ‘supergroup’ Perviae deals with morphology, secondary chemistry, habitat requirements and distribution in Poland. Six taxa have been accepted for the Polish lichen biota, namely, C. cenotea, C. crispata var. crispata, C. crispata var. cetrariiformis, C. glauca, C. parasitica, and C. squamosa; the occurrence of the two previously reported species, C. strepsilis and C. subfurcata has not been confirmed. The chemical races of the species and their frequency in Poland are indicated and a key for the taxa of ‘supergroup’ Perviae is provided. Additionally, two species, C. caespiticia and C. scabriuscula, which are frequently confused with some species of Perviae, were included in the revision.