Abstract
Auriculariales
is an important order of wood-inhabiting fungi, accommodating a high diversity of taxa with complex evolutionary relationships. Within this order, the generic boundaries and species diversity of
Basidiodendron
have remained incompletely resolved. Morphologically, the genus is characterized by annual, resupinate basidiomata, a monomitic hyphal system with clamped generative hyphae, longitudinally septate four-celled basidia with well-developed or indistinct involucres, and globose to subglobose basidiospores exhibiting smooth, warted, or spiny walls. Based on an integrative approach combining morphological characterization and multigene phylogeny inferred from ITS, nrLSU,
RPB
1,
RPB
2, and
TEF
1 sequence data, nine new species of
Basidiodendron
are formally introduced, namely
B. album
sp. nov
.,
B. arachnoideum
sp. nov
.,
B. dehongense
sp. nov
.,
B. fragilissimum
sp. nov
.,
B. odontoideum
sp. nov
.,
B. rigidum
sp. nov
.,
B. ruiliense
sp. nov
.,
B. tenissimum
sp. nov
., and
B. zhaotongense
sp. nov
. Detailed morphological descriptions, illustrations, and phylogenetic evaluations are provided for all newly described taxa. The generated multilocus dataset represents a substantial advance in understanding species diversity and phylogenetic relationships within the genus. This study significantly enriches knowledge of wood-inhabiting fungi and provides a more robust taxonomic framework for future research on
Basidiodendron
and related taxa in
Auriculariales
.