Crepidotus crocophyllus found in Costa Rica and Mexico and revision of related species in subsection Fulvifibrillosi.

The study of Crepidotus specimens collected in Costa Rica and Mexico revealed that C. crocophyllus occurs in the tropical and subtropical forests of both countries. Type specimens of seven species related to C. crocophyllus in subsection Fulvifibrillosi s. Hesler and Smith were re-examined. Based on the morphological features, specimens supporting C. appalachianensis, C. aureifolius, C. distortus, C. subaureifolius and C. subnidulans are interpreted to be C. crocophyllus, thus all herein are proposed as its synonyms. Furthermore A. nephrodes is confirmed as a synonym of Crepidotus crocophyllus while Agaricus malachius, long considered contaxic with the former, is proposed as synonym of Crepidotus applanatus. The known records of C. crocophyllus indicate a wide but fragmented range of extension of the taxon throughout the Americas. Description, illustrations of microscopic features and discussions are provided.