Amazonian bird's nest fungi (Basidiomycota): Current knowledge and novelties on Cyathus species

The genus Cyathus is historically subsampled in the Amazon Forest, which is a potential source of striking taxonomic richness. In this paper, a checklist of Amazonian Cyathus species with detailed descriptions, illustrations and comments of five uncommon species are given. A new species named C. albinus is proposed with morphological and molecular data, being mainly characterized by a light color hirsute exoperidium contrasting with a dark brown emplacement and basidiospores ovoid to elliptical. Three other species, C. amazonicus, C. earlei and C. triplex, are recorded for the first time from their localities. Also, polyphyly is detected into striatum infra-generic group after the addiction of tropical species, but a subclade containing Amazonian species was highly supported.