Three new species in the lichen genus Piccolia (Biatorellaceae, lichenized Ascomycota) from the Palaeotropics

Background – As part of taxonomic revisions of tropical African lichens, two species of Piccolia are described as new to science while a third unknown one collected in the Solomon archipelago was kindly send to us by the second author. Material and Methods – Morphology was studied using a stereo and light microscope. Chemistry was studied with spot tests and TLC. Key results – P. congolensis Van den Broeck, Aptroot & Ertz sp. nov. was collected twice in the Democratic Republic of the Congo and is characterized notably by a thallus with KC+ orange soralia. The material recorded recently from Reunion Island as P. elmeri (Vain.) Hafellner was shown to represent a different species characterized by a completely dark brown excipulum and is described here as P. kalbii Van den Broeck & Ertz sp. nov. P. nivea Van den Broeck, Aptroot & Ertz sp. nov. is only known from the type location on the Solomon archipelago and is characterized by grey pruinose ascomata and a thallus resembling a leprose crust. A worldwide key to the genus is provided.