Four new species of Entoloma subgen. Cubospora (Entolomataceae, Agaricales) from Yunnan Province, China

Species of <i>Entoloma</i> are exceptionally diverse and widely distributed, with cuboid-spored members occurring mainly in subtropical to tropical regions. These cuboid-spored taxa are primarily classified into two subgenera, E. subg. Cuboeccilia and E. subg. Cubospora. During surveys conducted in Yunnan Province, a representative subtropical region of China, four new species belonging to E. subg. Cubospora were identified through multigene phylogenetic analyses (ITS, LSU, <i>rpb2</i>, and <i>tef1</i>) combined with detailed morphological observations. <i>Entoloma acutiflavum</i> is distinguished by its yellow basidiomata, papillate pileus, heterogeneous lamellar edge, and the presence of clamp connections. <i>Entoloma bichromum</i> can be recognized by a centrally papillate pileus, serrate pileal and lamellar margins, and clavate to cylindrical pleurocystidia that are flexuous, furcate, or occasionally ventricose. <i>Entoloma guttuliferum</i> is characterized by its yellowish-white to white papillate pileus, clavate to elongated clavate terminal cells in both the pileipellis and stipitipellis, and pigmented cystidia, lamellar trama, pileipellis, and stipitipellis. <i>Entoloma rufosquamulosum</i> is identified by its reddish-brown to grayish-violet squamose pileus, with reddish-brown pigments present in the upper hyphal layer and terminal cells of the pileipellis. Detailed descriptions, line drawings, habitat photographs, SEM micrographs, and comparisons with morphologically and phylogenetically related taxa are provided. A key to the species of Entoloma subg. Cubospora from China is also included.