The Diversity and Taxonomy of Thelephoraceae (Basidiomycota) with Descriptions of Four Species from Southwestern China

Taxonomy plays a central role in understanding the diversity of life, translating the products of biological exploration and discovery specimens and observations into systems of names that settle a "classification home" to taxa. The ectomycorrhizal basidiomycetes family Thelephoraceae has been understudied in subtropical ecosystems. Many species of Thelephoraceae are important edible and medicinal fungi, with substantial economic value. Four new species, <i>Thelephora resupinata</i>, <i>T. subtropica</i>, <i>T. yunnanensis,</i> and <i>Tomentella tenuifarinacea</i>, are proposed based on a combination of the morphological features and molecular evidence. <i>Thelephora resupinata</i> is characterized by the resupinate basidiomata having a tuberculate pileal surface hymenial, and the presence of the subglobose to globose basidiospores (9-12 × 7-9 µm). <i>T. subtropica</i> is solitary coriaceous infundibuliform gray-brown basidiomata with a presence of the subclavate basidia and subglobose to globose basidiospores (6-8 × 5-7 µm). <i>T. yunnanensis</i> is typical of the laterally stipitate basidiomata having a smooth, umber to coffee hymenial surface, a monomitic hyphal system with clamped generative hyphae, and the presence of the subglobose basidiospores (7-10 × 6-8 µm). <i>Tomentella tenuifarinacea</i> is typical of the arachnoid basidiomata having a smooth, gray, or dark gray hymenial surface, a monomitic hyphal system with clamped generative hyphae, and the presence of the subglobose to globose basidiospores (7-9 × 6-8 µm). Sequences of ITS+nLSU+mtSSU genes were used for the phylogentic analyses using maximum likelihood, maximum parsimony, and Bayesian inference methods. The three genes' (ITS+nLSU+mtSSU) phylogenetic analysis showed that the genera <i>Thelephora</i> and <i>Tomentella</i> grouped together within the family Thelephoraceae and three new species were nested into the genus <i>Thelephora</i>, and one new species was nested into the genus <i>Tomentella</i>.