A phylogenetic overview of Squamanita, with descriptions of nine new species and four new combinations

Nuc rDNA internal transcribed spacer region ITS1-5.8S-ITS2 (ITS barcode) sequence data from eight type specimens of previously described Squamanita species were obtained. Phylogenetic analysis of ITS and partial nuc 28S rDNA data revealed Squamanita as paraphyletic splitting into two monophyletic groups, which we recognize as the genera Squamanita and Dissoderma. We accept 14 Squamanita and nine Dissoderma species, provide the first sequences of 13 of these, and describe six new species of Squamanita and three new species of Dissoderma. We transfer three species of Squamanita into Dissoderma, one into Cystoderma, and treat S. basii and S. umbilicata as synonyms of D. paradoxum. Squamanita can be distinguished from Dissoderma by the generally larger fleshier basidiomata with a tricholomatoid or amanitoid stature and yellowish to tawny brown pileus and often similarly colored stipe. Most species have cheilo- and pleurocystidia. Species of Dissoderma are small, collybioid or mycenoid, lack cystidia, and the pileus and often upper stipe are purplish gray. Both genera parasitize basidiomata of other agarics.本研究获取了8份已发表鳞伞属（Squamanita）物种模式标本的核核糖体DNA（nuclear ribosomal DNA, Nuc rDNA）内部转录间隔区ITS1-5.8S-ITS2（ITS条形码）序列数据。基于ITS序列及部分核28S核糖体DNA（nuc 28S rDNA）数据的系统发育分析显示，鳞伞属为并系群，可划分为两个单系支系，本研究将其分别界定为鳞伞属与异皮伞属（Dissoderma）。本研究确认鳞伞属含14个物种、异皮伞属含9个物种，其中13个物种的序列为首次报道，并描述了鳞伞属的6个新种及异皮伞属的3个新种。本研究将3个原隶属于鳞伞属的物种移至异皮伞属，1个物种移至囊皮伞属（Cystoderma），并将S. basii与S. umbilicata处理为D. paradoxum的同物异名。鳞伞属可通过以下特征与异皮伞属区分：担子果（basidiomata）通常更大、肉质，体型呈口蘑型（tricholomatoid）或鹅膏型（amanitoid），菌盖呈淡黄色至黄褐色，菌柄常具相似色泽。多数物种具备缘囊体与侧囊体。异皮伞属物种体型较小，呈小皮伞型（collybioid）或粪伞型（mycenoid），无囊状体，菌盖及菌柄上部常呈紫灰色。两属物种均寄生于其他伞菌的担子果上。