Gregorella humida, a new lichen for Belgium, and notes on the Belgian status of two other cyanolichens, Fuscopannaria nebulosa and Protopannaria pezizoides. – During surveys of abandoned quarries in Entre-Sambre-et-Meuse in recent years, two superficially similar cyanolichens considered extinct or absent from Belgium were collected. The first, Gregorella humida (Arctomiaceae), is reported for the first time from Belgium. The species colonizes the soil of a kaolin sand quarry in Oret. It was only collected once in 2004, so this pioneer lichen could already have disappeared due to forest recolonization and backfilling of the quarry. The second, Fuscopannaria nebulosa (Pannariaceae), was rediscovered in Belgium after more than a century of absence. The species colonizes schistose sandstone walls of two abandoned quarries, as well as a schistose slope in ditch by the roadside. The recent record (2006) of Protopannaria pezizoides in Belgium (Villers-sur-Lesse) is erroneous. The herbarium specimen is shown to belong to F. nebulosa on the basis of morphological characters (asci and spore type) and ITS gene sequencing. Protopannaria pezizoides must therefore be considered extinct in Belgium, the last observations dating from before 1867.