Nomenclatural remarks on Galdieria (Galdieriaceae, Cyanidiophytina, Rhodophyta) with description of three new species and a new lectotypification

Cynanidiophytina are a subdivision of Rhodophyta represented by unicellular organisms often occurring in extreme or acidophilous environments and object of several ecological, physiological, phylogenetic, ontogenetic, and molecular studies. Recently, the genus Galdieria, a Cyanidiophytina member that includes four species (out ofeleven in the whole subdivision), has been accommodated into a monogeneric order after an extensive taxonomic revision. However, the taxonomy of this group has not bee completely assessed. In this contribution, some nomenclatural issues about Galdieriaceae are discussed, three new species are published validating previous names, and revised types supporting the current usage of Galdieriasuphuraria are presented.