Molecular phylogenetics has revolutionized the taxonomy of crustose lichens and revealed an extensive amount of cryptic diversity. Resolving the relationships between genera in the crustose lichen family Tephromelataceae has proven difficult and the taxon limits within the genus Calvitimela are only partly understood. In this study, we tested the monophyly of Calvitimela and investigated phylogenetic relationships at different taxonomic levels using an integrative taxonomic approach. We performed a global sampling of all species currently assigned to Calvitimela and conducted additional sampling of C. melaleuca sensu lato across Norway. We included 108 specimens and produced more than 300 sequences from five different loci (ITS, LSU, MCM7, mtSSU, TEF1-α). We inferred phylogenetic relationships and estimated divergence times in Calvitimela. Moreover, we analyzed chemical and morphological characters to test their diagnostic values in the genus. Our molecular phylogenetic results show evolutionarily old and deeply divergent lineages in Calvitimela. The morphological characters are overlapping between divergent subgenera within this genus. Chemical characters, however, are largely informative at the level of subgenera, but are often homoplastic at the species level. The subgenus Calvitimela is found to include four distinct genetic lineages. Detailed morphological examinations of C. melaleuca s. lat. reveal differences between taxa previously assumed to be morphologically cryptic. Furthermore, young evolutionary ages and signs of gene tree discordance indicate a recent divergence and possibly incomplete lineage sorting in the subgenus Calvitimela. Phylogenetic analysis and morphological observations revealed that C. austrochilensis and C. uniseptata are extraneous to Calvitimela (Tephromelataceae). We also found molecular evidence supporting C. septentrionalis being sister to C. cuprea. In the subgenus Severidea, one new grouping is recovered as a highly supported sister to C. aglaea. Lastly, two fertile specimens were found to be phylogenetically nested within the sorediate species C. cuprea. We discuss the need for an updated classification of Calvitimela and the evolution of cryptic species. Through generic circumscription and species delimitation we propose a practical taxonomy of Calvitimela.

分子系统发生学彻底改变了壳状地衣的分类学，并揭示了广泛的神秘多样性。事实证明，解决硬壳地衣科 Tephromelataceae 属之间的关系很困难，并且对Calvitimela属内的分类群限制也只有部分了解。在这项研究中，我们测试了Calvitimela的单系性，并使用综合分类方法研究了不同分类水平的系统发育关系。我们对目前归属于Calvitimela的所有物种进行了全球采样，并对挪威各地的C. Melaleuca sensu lato进行了额外采样。我们纳入了 108 个样本，并从 5 个不同基因座（ITS、LSU、MCM7、mtSSU、TEF1-α）生成了 300 多个序列。我们推断了Calvitimela的系统发育关系并估计了分歧时间。此外，我们分析了化学和形态特征，以测试它们在该属中的诊断价值。我们的分子系统发育结果显示了 Calvitimela 进化古老且分歧很大的谱系。该属内不同亚属之间的形态特征重叠。然而，化学特征在亚属水平上很大程度上提供了信息，但在物种水平上通常是同质的。人们发现Calvitimela亚属包括四个不同的遗传谱系。C. Melaleuca s的详细形态学检查。纬度 揭示了以前被认为在形态上神秘的类群之间的差异。此外，年轻的进化年龄和基因树不一致的迹象表明Calvitimela亚属最近出现了分歧，并且谱系排序可能不完整。系统发育分析和形态学观察表明，C. austrochilensis和C. uniseptata与Calvitimela（Tephromelataceae）无关。我们还发现了分子证据支持C. septentrionalis是C. cuprea的姐妹。在Severidea亚属中，发现了一个新的类群，它是C. aglaea的姐妹类，受到高度支持。最后，两个可育的标本被发现在系统发育上嵌套在 sorediate 物种C. cuprea中。我们讨论了更新Calvitimela分类的必要性和隐秘物种的进化。通过属属范围和物种界定，我们提出了Calvitimela的实用分类法。