A SYNOPSIS OF THE LICHEN GENUS PSILOPARMELIA (ASCOMYCOTINA, PARMELIACEAE)

The genus Psiloparmelia Hale has its center of diversity in the high Andes Mountains of South America, but also occurs in the mountains of southern Africa. The genus is characterized by a velvety lower surface without rhizines, isolichenan in the cell walls, a rudimentary pored epicortex, unusual distribution of secondary metabolites, and significant concentrations of both atranorin and usnic acid in the upper cortex. Psiloparmelia has secondary-product chemistry characterized by beta-orcinol depsides and depsidones and fatty acids. A total of 24 known compounds is reported for the genus, based upon thin-layer and high-performance liquid chromatographic analyses of 189 specimens. Psiloparmelia is now considered to comprise 12 species; nine are here described as new and one is a new combination.