Two new species of Collybiopsis (Agaricales, Omphalotaceae) from Eastern North America.

Two small gymnopoid fungi from the southern Appalachian Mountains and Massachusetts, Collybiopsiscomplicata sp. nov. and C.prolapsis sp. nov. , are identified and described. A new generic nrITS-LSU phylogeny of Collybiopsis places C.complicata and C.prolapsis in a small clade together with C.minor , and an unknown taxon from Arkansas. This clade adds to the growing circumscription of Collybiopsis (= Marasmiellus ).