Two new species in the Lulesia fallax complex (Entolomataceae, Agaricales) from Europe (Fennoscandia and Switzerland), Lulesia neofallax comb. nov., new records of recently described species of Lulesia, and notes on Clitocybe alachuana

Lulesia fallacioides (from Finland) and L. parvifallax (from Switzerland) are described as new species, based on both a morphological and molecular approach, in the L. fallax complex (Lulesia subgen. Paraclitopilus), a morphology-delimited aggregate of species sharing white basidiomes and a bitter context. Compared to L. fallax, the former differs mainly by wider spores and a gelatinized pileipellis and the latter by smaller basidiomes and shorter spores. The recently described Clitocella neofallax from China is here combined in Lulesia. New collections of L. colorata and L. solaris made in Italy and Finland have allowed us to better understand the distinctive features and/or to extend the distribution area of these recently established species. The presence of L. fallax, L. mundula and L. obscura in Finland is here molecularly confirmed for the first time. Finally, a full morphological description of L. alachuana, a North American species so far described from Florida, is provided based on ancient (holotype included) and recent collections.本研究基于形态学与分子生物学方法，对分布于芬兰的假长根小菇（Lulesia fallacioides）及瑞士的细变小菇（L. parvifallax）开展分类学研究，将二者确立为长根小菇复合群（Lulesia亚属Paraclitopilus）下的新物种；该复合群为基于形态学界定的物种类群，其成员均具有白色担子果与味苦的菌肉。与长根小菇（L. fallax）相比，假长根小菇主要差异在于孢子更宽大且具有胶质感的菌盖表皮，细变小菇则以更小的担子果与更短小的孢子为主要鉴别特征。本研究将此前发表于中国的新变杯伞（Clitocella neofallax）组合至长根小菇属（Lulesia）。通过对采自意大利与芬兰的变色长根小菇（L. colorata）及日光长根小菇（L. solaris）的新标本进行研究，我们得以更清晰地明确这两个近年发表物种的鉴别特征，并拓展了它们的分布范围。本研究首次通过分子生物学方法证实，芬兰境内存在长根小菇（L. fallax）、淡色长根小菇（L. mundula）及暗长根小菇（L. obscura）。最后，本研究基于馆藏标本（包含主模式标本）与近年采集的标本，对此前仅由美国佛罗里达州报道的北美物种阿拉楚阿长根小菇（L. alachuana）进行了完整的形态学描述。