Szczepańska, K. & Kossowska, M. 2017. Cetrariella commixta and the genus Melanelia (Parmeliaceae, Ascomycota) in Poland. — Herzogia 30: 272–288.
The paper presents the distribution and ecology of Cetrariella commixta and the species of Melanelia occurring in Poland. Morphological and chemical analyses of herbarium material confirmed the presence of three species of the studied group, earlier recorded in the country: Cetrariella commixta, Melanelia hepatizon and M. stygia. Cetrariella commixta is a rare species with distribution limited to the Sudetes. None of the previously reported localities of this taxon in the Carpathians were confirmed. Chemotaxonomic studies demonstrated the presence of two chemotypes of C. commixta in the country, but no correlation between chemical races and distribution was observed. In contrast, Melanelia hepatizon and M. stygia proved to be rather common in Poland, where their distribution is restricted to the mountain regions. Additionally, Melanelia agnata is reported here as a new species to Poland. It is the rarest species of the studied group, occurring only in few localities in the High Tatras. It should be considered critically endangered in the country.