Data from: A review of the lichen genus Phlyctis in North America (Phlyctidaceae) including the description of a new widespread saxicolous species from eastern North America

A review of the crustose lichen genus Phlyctis in North America is presented derived from large-scale studies of chemical, morphological, and molecular data (ITS and mtSSU). Five species are recognized based on a combination of morphological and chemical characters, namely P. agelaea, P. argena, P. boliviensis, P. speirea and the newly described P. petraea. Analyses of molecular data supported the recognition of P. boliviensis and P. petraea but recovered P. agelaea, P. argena or P. speirea in a single clade with little internal phylogenetic structure, suggesting their circumscription based on reproductive mode and thallus morphology requires further study. An account is provided that includes an identification key, discussion of each species, distribution maps and illustrations of morphology. Phlyctis petraea, provisionally named more than a decade ago, is described as new to science. Molecular phylogenetic analyses using ITS and mtSSU sequence data both confirm the placement of P. petraea in Phlyctis and demonstrate two known chemotypes (one with norstictic acid and one with norstictic and stictic acids) are not reciprocally monophyletic and should be treated as variants of a single species. Psathyrophlyctis, described as a member of the Phlyctidaceae, is discussed and treated as a member of the Lecanorales incertae sedis.

本研究基于大规模化学、形态学及分子数据（ITS与线粒体小亚基rDNA，mtSSU），对北美地区壳状地衣叶点衣属（Phlyctis）开展了系统性综述。本研究结合形态与化学特征，共确认5个物种：P. agelaea、P. argena、P. boliviensis、P. speirea以及新描述的P. petraea。分子数据分析支持P. boliviensis与P. petraea的物种地位，但将P. agelaea、P. argena及P. speirea聚为一个内部系统发育结构极弱的单演化支，提示基于繁殖方式与地衣体形态对该类群进行分类界定尚需进一步研究。本综述包含物种检索表、各物种详细讨论、分布地图及形态解剖图版。P. petraea曾于十余年前被临时命名，本次正式发表为新物种。基于ITS与mtSSU序列数据的分子系统发育分析，既确认了P. petraea隶属于叶点衣属（Phlyctis），同时表明两种已知化学型（一种仅含诺司替酸，另一种含诺司替酸与石花酸）并非互为单系群，应视为同一物种的不同变种。曾被归入叶点衣科（Phlyctidaceae）的Psathyrophlyctis属，本次研究将其纳入讨论并归为茶渍目（Lecanorales）下分类位置未定类群。