Language: English with trilingual summary in English, German, and Spanish
In a large collection of leaves of various plants from Costa Rica made recently by the author, about 220 species and varieties of foliicolous lichens have been found, increasing the number of taxa known from this territory by 155 to 228. Apart from Brasil this proved to be the highest species number of all countries so far investigated. Based upon the present collection a comprehensive survey of the foliicolous lichen flora of Costa Rica is given. Keys to genera, species and varieties are provided, together with numerous illustrations, and most taxa are discussed in detail.