Coprinopsis igarashii sp. nov., a coprophilous agaric fungus from Hokkaido, northern Japan

• A new fimicolous fungus, Coprinopsis igarashii is described from Japanese deer dung.
• This new taxon has three types of pileus veil elements.
• The morphological characters of pileus veil elements discriminate this species from all other coprinoid species.

Coprinopsis igarashii (Basidiomycota, Agaricales, Psathyrellaceae) is a new fimicolous coprinoid fungus from Hokkaido, Japan. In macro- and micro-morphology, this species is similar to C. candidolanata but differs in having globose elements in the universal veil and heart-shaped basidiospores. The results of phylogenetic analysis with the nuclear ribosomal internal transcribed spacer (ITS) data also support this new taxon.