Temperature preferences and small-scale distribution patterns of four Dermatocarpon taxa in the catchment areas of two Bulgarian rivers were analyzed. Taxa with an overall alpine or arctic-alpine distribution were restricted to microhabitats with the lowest water and rock surface temperatures. A trend for increasing Dermatocarpon rivulorum thallus diameter and colony size (aggregates of thalli) with decreasing temperature was identified. Data on pH and conductivity of the water for the study sites are provided for all taxa. Dermatocarpon arnoldianum is reported for the first time from Bulgaria, confirmed by ITS sequence data, and its known range extends to South-East Europe. All previous records of D. rivulorum from Bulgaria were based on misidentified specimens of D. arnoldianum. Freshwater taxa of Dermatocarpon are proposed as a tool for monitoring the biological effects of temperature changes due to global climate change. Thallus and colony size are recommended as additional features for monitoring populations of threatened Dermatocarpon species.

The crustose genus Staurothele (Verrucariaceae, Ascomycota) is a common component of the lichen flora from subneutral to alkaline silicate rocks in temperate to cold-temperate climates. Our field study in the karst system of northern Vietnam showed that it is also common on dry to humid limestone in the wet tropics. Molecular data revealed that species of Staurothele from Vietnam belong to an unnamed clade sister to the genus Endocarpon, together with the tropical Australian species Staurothele pallidopora and Staurothele diffractella, a North American species recently transferred to Endocarpon based on molecular data. The genus Willeya is here resurrected for this clade of crustose epilithic Staurothele with pale ascospores. Eight new combinations are proposed and three new species of Willeya are described from Vietnam. Sampling tropical members of a lichen family previously mostly known from temperate areas contributed significantly to improving its generic classification.

The generic name Gemmaspora gen. nov. is introduced for the lichenicolous fungus originally described as Adelococcus lecanorae, a species previously known only from the type collection made in Syria in 1934, but which has now been recollected twice in Turkey. It is distinguished by perithecia that have a double wall layer in which the outer is hyaline and the inner brown, and by brown ascospores with two thick wall layers and an inner delicate distoseptum. A full description and illustrations are provided based mainly on the modern collections one of which is designated as an epitype for the name as no perithecia could now be found on the holotype. The genus is referred to Verrucariales on the basis of the structure of the ascomata and asci, and the new combination Gemmaspora lecanorae comb. nov. made. The holotype also supports Lichenostigma elongata and Muellerella lichenicola which may be the first reports of those two species from Syria.