Taxonomy and phylogeny of Dichostereum (Russulales), with descriptions of three new species from southern China

摘要

Nine species of Dichostereum were subjected to phylogenetic analyses, based on a combined dataset of ITS1-5.8S-ITS2-nrLSU-tef1 sequences. The morphology of specimens collected from China and Australia were studied. Three species, D. austrosinense, D. boidinii and D. eburneum, collected from southern China, are described and illustrated as new to science, based on the morphological and molecular evidence. Dichostereum austrosinense is characterised by the relatively large gloeocystidia (80–130 × 8–15 μm) and basidiospores (7.3–8 μm in diam.) with large warts and crests. Dichostereum boidinii is distinguished by its thick basidiomata and relatively small basidiospores (5.5–6.5 μm in diam.) with large warts and crests. Dichostereum eburneum is unique in having pale basidiomata growing on bark of living Castanopsis, abundant crystals in the context and basidiospores with dense and large ornamentations. A key to the 5 species of Dichostereum in China is given.