Mushrooms with a thin-fleshed pileus that becomes plicate on opening, deliquescent lamellae and dark brown to blackish basidiospores are commonly called coprinoid mushrooms. The genus Coprinellus is one of the important lineages of coprinoid mushroom in the family Psathyrellaceae. Species-level taxonomy in Coprinellus is based mainly on the presence or absence and the structure of veil and cystidia on the pileus, of cystidia on the lamellae and on basidiospore morphology. In this study, four new species of Coprinellus (Co.campanulatus, Co.disseminatus-similis, Co.pakistanicus and Co.tenuis) are described from Pakistan. Species descriptions are based on morphological and molecular data. Phylogenetic analyses based on nuc rDNA ITS region show that the new species Co.campanulatus and Co.disseminatus-similis are clustered in a clade including members of section Micacei; Co.tenuis falls in a clade with members of section Domestici; and Co.pakistanicus recovered in a separate clade adjacent to other recently described clades of genus Coprinellus. Morpho-anatomical descriptions of the new species and comparison with closely allied taxa are provided. With this study, the number of known species of Coprinellus in Pakistan has reached eight.
Keywords: Coprinellus sect. Micacei; Coprinellus section Domestici; coprinoid fungi; taxonomy.