Collybiopsis pakistanica (Omphalotaceae, Agaricales, Basidiomycota), a new mushroom species from Margalla Hills, Pakistan, and two new combinations

A new species, Collybiopsis pakistanica, from Margalla Hills National Park, Pakistan, is described based on micro-morphological and molecular phylogenetic analyses. This species is characterized by its milky white pileus, yellowish orange or light yellow to orange at central disc and margins, lacrymoid basidiospores, cheilocystidia with median construction, and broadly utriform and clavate to narrowly utriform pleurocystidia and epithelioid hymeniderm pileipellis. Its placement as a new taxon of Collybiopsis is confirmed by phylogenetic analyses of ITS and nrLSU sequences. Two new combinations, Collybiopsis ugandensis and Collybiopsis pleurocystidiata are also proposed as these species are transferred from Gymnopus., ,本研究基于微观形态学与分子系统发育分析，对采自巴基斯坦马尔加拉山国家公园的新种巴基斯坦小皮伞（Collybiopsis pakistanica）进行了详细描述。该新种的形态特征为：菌盖呈乳白色，菌盖中央及边缘呈浅黄橙色至橙黄色；担孢子呈泪滴形；缘囊体具中部构造；侧囊体为宽瓶形、棒形至狭瓶形；菌盖表皮为上皮型拟子实层结构。通过对内部转录间隔区（ITS）及核核糖体大亚基（nrLSU）序列的系统发育分析，证实该物种隶属于小皮伞属（Collybiopsis）的新分类群。此外，因两个原隶属于裸柄伞属（Gymnopus）的物种需转入小皮伞属，故提出两个新组合：乌干达小皮伞（Collybiopsis ugandensis）与侧囊小皮伞（Collybiopsis pleurocystidiata）。