Changbai wood-rotting fungi 13.: Antrodia sensu lato

This paper deals with the species of Antrodia (Basidiomycota) in northeastern China. Seventeen species are found in the area, and a key was compiled for the species so far recorded. Statistical variations of spore dimensions are included in the key. A new species, Antrodia leucaena YC. Dai & Niemela, collected on Populus davidiana, is described and illustrated. It is characterized by resupinate to effused-reflexed basidiocarps, and white to cream colour of pore surface, turning brownish when drying. The hyphal structure is dimitic with clamps on generative hyphae, spores are cylindric, and rhomboid or irregular crystal clusters are common in its context and trama. In addition, a non-fertile hymenium has thin-walled hyphidia with apical encrustations. The species seems to be living exclusively on Populus. The closest relatives are A. serialis (Fr.) Donk (having different spores, different set of colours, and growing on conifers), Antrodia macra (Sommerf.) Niemela (a resupinate species), and A. pulvinascens (Pilat) Niemela (producing pseudopilei). Five other Antrodia species are briefly discussed.