Two new Crypthonia species and a new Syncesia from Chapada do Araripe, Ceará, NE Brazil (Ascomycota: Arthoniales), with a key to Crypthonia

Abstract

AbstractTwo new species of the small genus Crypthonia are described from the Chapada do Araripe, an isolated table mountain in the state of Ceará, in NE Brazil. Both share the thallus and ascoma organization with the other known species of the genus, and are mainly characterized by differences in ascospores and chemistry. Crypthonia lichexanthonica A. A. Menezes, M. Cáceres & Aptroot has 7-septate ascospores and contains lichexanthone in the thallus, and C. submuriformis A. A. Menezes, M. Cáceres & Aptroot has (sub)muriform ascospores and also contains lichexanthone, but only in the ascigerous areas. A key to all known species of the genus Crypthonia is provided, in which Crypthonia olivacea Frisch & G. Thor is newly reported from Argentina. The new species Syncesia byssolomoides A. A. Menezes, M. Cáceres & Aptroot is described from the same area. It also has a thin byssoid thallus, but differs by the narrowly fusiform ascospores and by containing psoromic acid. It differs from all Syncesia species by the absence of carbonization and the presence of psoromic acid. The epiphytic lichen flora in this Caatinga forest area is dominated by crustose lichens, with Graphis and Polymeridium as the most speciose genera.