A first approach to the lichen flora of Guinea-Bissau.

Twenty lichen taxa are reported as new from Guinea-Bissau; one is new to continental Africa, seven are reported for the first time from western Africa and one is described here as new to science, namely Pertusaria guineabissauensis, which has eight hyaline, smooth-walled ascospore per ascus and contains stictic acid. [ABSTRACT FROM AUTHOR]