Tylocinum is no longer monotypic: Tylocinum brevisporum sp. nov. (Boletales, Boletaceae) from northern Thailand

Tylocinum Y.C. Li & Zhu L. Yang 2016 is a Boletaceae genus belonging in subfamily Leccinoideae. It was described in 2016 from China and, prior to this study, it contained only one species, T. griseolum Y.C. Li & Zhu L. Yang 2016. During our survey of Boletaceae from Thailand, we collected some specimens that could be identified as a Tylocinum species, different from T. griseolum. The bolete specimens, collected in forests dominated by Dipterocarpaceae and Fagaceae in northern Thailand, are described as Tylocinum brevisporum Raghoonundon & Raspé sp. nov. Macroscopic and microscopic descriptions with illustrations are provided, as well as a 3-gene phylogeny, which confirms the new taxon’s position in Tylocinum. Tylocinum brevisporum differs from the only other known Tylocinum species (T. griseolum) by its brownish-grey colour, greyish-orange to brownish-orange colour change in the hymenophore when bruised, smaller pores (≤ 0.5 mm), longer tubes (up to 6 mm long), shorter and narrower basidiospores, longer and broader basidia and longer pleurocystidia relative to cheilocystidia. T. brevisporum is the second species from the genus Tylocinum and the only one to be found outside China thus far.