Diversity and systematics of hypogeous (truffle-like) fungi in the Leccinoideae (Boletaceae, Boletales) with emphasis on Japanese taxa

Abstract

The term “hypogeous fungi” is often broadly applied to fungi that form subterranean sporocarps with morphologically and ecologically adapted to specific habitats. Hypogeous fungi include truffles, truffle-like or secotioid fungi and some gasteroid sporocarp-forming fungi in Mucoromycotina and Glomeromycotina. Systematic studies in Japanese hypogeous fungi have drastically been increased in the last decade. It is currently recognized that species diversity of hypogeous fungi in the Japanese Archipelago is remarkably high. In this review, I focus on recent progress in the systematics of Japanese hypogeous fungi that are phylogenetically related to the bolete genera Leccinum and Leccinellum in Leccinoideae (Boletaceae, Boletales). These fungi belong to four genera with truffle-like basidiomata (i.e., Chamonixia, Octaviania, Rossbeevera and Turmalinea). I give brief descriptions of all infrageneric taxa currently known from Japan as well as the Japanese taxa recently excluded from Leccinoideae.