Three new species of <i>Smithiomyces</i> from tropical Asia support an amphi-Pacific disjunct distribution in the genus

<i>Smithiomyces</i> is reported for the first time from tropical regions in China, thus expanding its known native geographic range from the Neotropics to tropical Asia. Phylogenetic evidence from four nuclear loci supports the monophyly of <i>Smithiomyces</i> and a close evolutionary relationship with the nonmonophyletic genera <i>Melanophyllum</i> and <i>Cystolepiota</i> in the Agaricaceae. Detailed morphological descriptions are provided for three newly described species from China: <i>S. asiaticus, S. heterosporus</i>, and <i>S. lepiotoides</i>. Illustrations of fresh basidiomata in the field, line drawings of key anatomical features, microscopic images of anatomical features, scanning electron microscope (SEM) images of basidiospores, and a key to known species of <i>Smithiomyces</i> are also provided.