Two new species of Boletopsis (Bankeraceae, Thelephorales) from Southwest China

Abstract

Two new species of Boletopsis, B. macrocarpa and B. tibetana, are described and illustrated from Southwest (SW) China based on morphology, ecology and phylogenetic analyses by the internal transcribed spacer regions (ITS) and the large subunit of nuclear ribosomal RNA gene (nLSU). Boletopsis macrocarpa is characterized by big basidiocarps (up to 18 cm in diam), guttulate basidiospores, and the presence of gloeoplerous hyphae in context and growing in pure forest of Pinus yunnanensis. Boletopsis tibetana is characterized by smaller pores (3–4 per mm), the presence of gloeoplerous hyphae in pileipellis, and the growth in forests of Picea. Phylogenetically, the two new species are grouped in two independent lineages nested in Boletopsis. In addition, one sample from Northeast China is temporarily treated as Boletopsis sp. 1 because of the single sample; another Chinese sample from SW China is sister to B. grisea in phylogeny, and it is treated as B. cf. grisea because the morphological difference between B. cf. grisea and B. grisea is indistinct. Furthermore, the main characteristics of Boletopsis species are listed, and a key to accepted species of Boletopsis is provided.