Data from: Phylogeny and taxonomy of an enigmatic sterile lichen

Crustose, asexually reproducing taxa represent a large component of lichen biodiversity that is often overlooked and underestimated; as a result, remarkable potential remains for discovery of new species in this neglected, polyphyletic group. For this study, ITS and mtSSU rDNA sequences were analyzed in conjunction with chemical and anatomical data to understand the systematic placement of an enigmatic, sterile lichen. This species, despite references in the literature, and being known for over half a decade, has remained undescribed due to our inability to integrate it into a higher-level taxonomic framework using morphology alone. Here we demonstrate the utility of a systematic methodology that combines molecular and non-molecular characters to place and circumscribe species of asexually reproducing lichens that are typically sterile. Based on our analyses, the new species, Caloplaca reptans, shows phylogenetic and morphological affinities to a broad group of Caloplaca species with gray thalli, including the type species of the genus, C. cerina. This study highlights that the family Teloschistaceae is morphologically more diverse than previously understood, and contains elements that cannot easily be placed in known 'species groups.'

壳状、无性繁殖的类群是地衣生物多样性的重要组成部分，却常被忽视与低估；因此，这一被忽视的多系群中仍蕴藏着发现新物种的巨大潜力。本研究结合内转录间隔区（ITS）与线粒体小亚基核糖体DNA（mtSSU rDNA）序列数据，以及化学与解剖学特征数据，旨在解析一种神秘不育地衣的系统分类位置。该物种虽早在逾五年前便已见诸文献且为人所知，却始终未能被正式描述——这是因为仅依靠形态学特征，我们无法将其归入高级分类框架之中。在此，我们展示了一套系统学研究方法的实用性：该方法整合分子与非分子特征，用以确定典型不育的无性繁殖地衣类群的分类地位并界定其物种。基于本研究的分析结果，新种匍匐橙衣（Caloplaca reptans）与一类具有灰色地衣体的橙衣属（Caloplaca）物种展现出密切的系统发育与形态学亲缘关系，其中包括该属的模式种C. cerina。本研究表明，黄枝衣科（Teloschistaceae）的形态多样性远超此前认知，其中包含了无法轻易归入现有‘物种群’的类群。