Lithocalla (Ascomycota, Lecanorales), a new genus of leprose lichens containing usnic acid

Abstract

AbstractThe identity of Lecanora ecorticata has been uncertain due to conflicting reports of the presence of zeorin and the loss of the holotype. Phylogenetic analysis suggests that the species probably belongs in Ramalinaceae, where it is the first leprose species reported. Zeorin was found to be absent in recently collected material of L. ecorticata, including specimens from the type locality, and the report of zeorin in the lost holotype is considered to be due to contamination. A new genus, Lithocalla, is erected to accommodate L. ecorticata and a second closely related species, that occurs in the Falkland Islands, is newly combined as Lithocalla malouina. A lectotype is selected for L. ecorticata. Lithocalla is characterized by a leprose thallus containing usnic acid with fatty acids and terpenoids, but no zeorin; ascomata and conidiomata are unknown.