Zduńczyk, A. & Kukwa, M. 2014. A revision of sorediate crustose lichens containing usnic acid and chlorinated xanthones in Poland. — Herzogia 27: 13–40.

The results of a revision of sorediate, crustose lichens containing usnic acid and chlorinated xanthones growing on all types of substrata in Poland are presented. This group of lichens has never been studied thoroughly in Poland or in any neighbouring country. The following taxa were confirmed: Biatora pontica, Haematomma ochroleucum var. ochroleucum, Lecanora compallens, L. conizaeoides, L. expallens, L. flavoleprosa, L. orosthea, L. soralifera, L. thysanophora, Lecidella elaeochroma f. soralifera, L. flavosorediata, L. scabra, L. subviridis, Mycoblastus alpinus and Pyrrhospora quernea. No material of Pertusaria flavicans was located in Polish herbaria. The holotype of Mycoblastus alpinus f. friesii described from Poland represents a typical M. alpinus. For each taxon, a description (based on studied material), data on the chemistry, distribution and habitat requirements, as well as notes on similar taxa, are provided. Distribution maps based on revised material from Poland are presented and an identification key for all taxa is provided.