Two new lecanoroid Caloplaca (Teloschistaceae) species from gneiss inselbergs in equatorial Brazil, with a key to tropical lecanoroid species of Caloplaca s. lat.

Abstract

AbstractGneiss inselbergs in the Caatinga region of Ceará in equatorial Brazil are literally covered with a wide diversity of caloplacoid lichens. This includes two closely related new saxicolous species of Caloplaca, both with the aspect of a Lecanora of the subfusca-aggregate: C. lecanorocarpa has a grey areolate bullate thallus with atranorin on a black prothallus, grey thalline apothecium margin, sessile apothecia with glossy dark brown disc, and ascospores of 10–12×5·0–5·5 μm, with a 5·0–5·5 μm thick septum; and the similar, related C. lecapustulata which mainly differs by the rimose thallus with irregular mushroom-shaped pustules. The phylogenetic position of the two new species has been assessed to be within the Caloplacoideae. A key to all tropical lecanoroid Caloplaca species is provided.