It has been reported that Sclerotium nivale Elenev causes winter damage (Sclerotium disease) to winter rye and turfgrass in the European part of Russia, Ukraine, and Estonia. This fungal name is invalid, and their biological characteristics are limited. Since all reports on this fungus and their disease are written in Russian and Estonian without our recent review (Tkachenko 2013), few phytopathologists outside the former Union of Soviet Socialist Republics know about this fungus. We found symptoms of Sclerotium disease in Moscow, Russia, and we obtained asexual spore-forming ascomycetous (absent clamp connections) and basidiomycetous (had clamp connections) isolates from their white sclerotia. “S. nivale” was composed of several fungal species of ascomycetes and basidiomycetes. The ascomycetous isolate had the ability to grow under the snow cover, and phylogenic analysis suggested that the ascomycetous isolate had high homology (98–99%) with genera of Karstenula and Paraphaeosphaeria. We previously reported sclerotia of Typhula sp. were formed ca. 2 weeks to 1 month after the snow melt, remained immature as mycelial aggregations after snow melt, and matured without snow. In addition, Paraphaeosphaeria included sclerotium parasites such as P. minitans. Several cold-adapted fungi infected basidiomycetous sclerotia of Typhula spp. and others. These findings suggested that ascomycetous S. nivale was the possibility of the mycoparasite under the snow.

Typhulaceae Jülich is one of the cold-adapted fungal families in basidiomycetes. Typhula (Pers.) Fr. and Pistillaria Fr. representing the family are distinguished from the morphology of a stipe to a hymenium (Fries 1821). The hymenium of Typhula is distinguishable from the stipe, but indistinguishable and consecutive in the genus Pistillaria. This taxonomic criterion is ambiguous, and consequently the opinion of Karsten (1882) has been widely accepted; I the genus Typhula, basidiomata develop from sclerotia, while basidiomata develop directly from substrata in the genus Pistillaris. But, Corner (1970) observed basidiomata of Pistillaria petasitis S. Imai in Hokkaido, Japan, from sclerotia. We collected irregular sclerotia of Typhula hyperborea H. Ekstr. from Upernavik, West Greenland. This specimen had a stipe-like structure on a Poaceae plant, and sclerotia developed on its tip. In August, P. petasitis in Hokkaido, Japan, formed basidiomata directly from substrates on the ground. Similar phenomena were found from other Typhula spp. in Japan. All of these fungi had the potential to produce sclerotia in culture, and as well as the capacity of mycelial growth at ambient air temperatures in each locality when samples were collected. These findings suggest that Typhula spp. developed basidiomata not only from the sclerotia dispersed by the basidiospores but also mycelia generated by the spore germination formed basidiomata multiple times depending on their growth environments.