A taxonomic revision ofCaloplaca herbidellaandC. furfuracea

Abstract

AbstractCaloplaca herbidella(Hue) H. Magn. andC. furfuraceaH. Magn. are two isidiate, epiphytic species in the large genusCaloplaca.Caloplaca herbidellain a strict sense is normally grey and fertile with thick, somewhat coralloid isidia, but orange, sterile forms with thin isidia also occur.Caloplaca furfuraceais superficially similar morphologically toC. herbidellas. str. but has thinner, more granular isidia and generally a darker grey colour. Doubts have been raised as to whetherC. furfuraceashould be acknowledged as a proper species or incorporated inC. herbidella. Using morphometric methods and molecular analysis of the nrITS DNA gene we show thatC. herbidellaandC. furfuraceaare two clearly separated species. Furthermore, the mainly sterile, orange form ofC. herbidellacan be regarded as a separate species that is here described asC. corallizaArup & Åkelius. All three species are described in detail, including photographs and notes on their ecology. Finally, new distribution maps for Europe show thatC. herbidellaandC. corallizaare widespread in Europe, but the latter is probably less common than the former.Caloplaca furfuraceais clearly very rare in Europe with only few collections from Switzerland and Sweden, but seems to be more common in North America.