Studies in Arthoniales s. lat

Abstract: The delimitation and nomenclature of the genus Chiodecton (16 spp.) and five related genera, Ancistrospora (1 sp.), Dichosporidium (6 spp.), Erythrodecton (2 spp.), Graphidastra (2 spp.) and Streimannia (1 sp.), are revised. The genera Ancistrospora, Erythrodecton and Streimannia are described and Graphidastra is erected as genus. Also, two new Chrysothrix species are described. A key of all species is given as well as typification and photos. A hypothesis of the cladistic relationships of all species but Chrysothrix granulosa and C. placodioides is presented and discussed.