Novel diversity in <i>Lactifluus</i> section <i>Gerardii</i> from Asia: five new species with pleurotoid or small agaricoid basidiocarps

<p>The ectomycorrhizal milkcap genus <i>Lactifluus</i> (Russulaceae) is commonly found in tropical and subtropical forests of Southeast Asia. During several sampling expeditions in Thailand, multiple collections of <i>Lactifluus</i> (<i>Lf</i>.) species with pleurotoid or small agaricoid basidiocarps were found. A molecular study was combined with a morphological study, in which the collections were compared with herbarium material. The molecular study indicated that four Thai collections belonged to undescribed species within <i>Lactifluus</i> section <i>Gerardii</i>, as was also the case for herbarium collections of a pleurotoid species from Nepal. One other collection from Thailand appeared closely related to <i>Lf. uyedae</i>, known only from Japan. Five species are described as new in the genus: <i>Lf. auriculiformis, Lf. gerardiellus, Lf. bhandaryi, Lf. pulchrellus</i>, and <i>Lf. raspei</i>.</p>