PROGRESS IN THE GENERIC DELIMITATION OF PARMELIA SENSU-LATO LICHENS (ASCOMYCOTINA, PARMELIACEAE) AND A SYNOPTIC KEY TO THE PARMELIACEAE

The validity of the many genera segregated from Parmelia s.l. in recent years is argued on the basis of the following characters: the nature of the upper cortical structure (pored epicorticate, nonpored epicorticate, pseudocyphellate); type of fungal cell wall polysaccharides (isolichenan, lichenan); ascocarp, pycnidial, spore, and pycnoconidial characters; chemistry of the upper cortex; and various thalline characters. The high degree of correlation between these and other secondary characters (medullary chemistry, ecology, geographic distribution) leads to a consistent taxonomy. A synoptic key to the genera of the Parmeliaceae is provided and key characters are listed for each of the 64 genera considered