Megacollybia rimosa (Agaricales), a new species from Brazil

A new species of Megacollybia is here described, besides the collection being the first occurrence of this genus to Brazil. This taxon is mainly recognized by its rimose to cracked pileus, pruinose stipe surface, short-clavate, subclavate to lageniform pileocystidia and by the presence of clamp-connections. A full description, discussion, photographs and drawings of the microstructures are provided.