, a New Species of the Section () from Japan

A novel species of section , namely, , is described and illustrated based on samples found in an oak woods dominated by , an evergreen oak, in Tottori Prefecture, western Japan. It is characterized by a conic-umbonate, dark-greenish olivaceous pileus with blackish innate fibrils; a whitish silky-fibrillose stipe, often faintly tinted pale yellow and with a narrowed subpointed base; subglobose to broadly elliptic spores; and fruiting in early winter. Phylogenetic analysis targeting the internal transcribed spacer region of the ribosomal RNA gene revealed that forms a well-supported clade sister to . Other morphologically and phylogenetically closely related species of the section are discussed.