Data from: The Wisdom of Fools: new molecular and morphological insights into the North American apodetiate species of Cladonia

The taxonomy of the North American apodetiate and superficially apodetiate species of Cladonia with persistent, primarily squamulose thalli (viz., C. apodocarpa, C. caespiticia, and C. petrophila) is revised using morphological, chemical, and ecological data in combination with molecular phylogenetic analyses of ITS1, 5.8S, and ITS2 sequence data. The results of this approach confirm some established taxonomic concepts in the group and raise doubts about others. The taxon known as C. apodocarpa is well supported by likelihood- and parsimony-based molecular phylogenetic inferences as well as morphology, chemistry, and ecology. However, molecular evidence gives an equivocal answer to the question of whether C. petrophila is a distinct monophyletic entity or if C. apodocarpa is nested within it. In addition, no phylogenetic structure is detected for the chemical races of C. petrophila with and without fumarprotocetraric acid, based on the markers used in these analyses. However, C. petrophila does remain well supported as a taxon by chemistry (i.e., the presence of sphaerophorin), morphology, and ecology. A morphologically and ecologically distinct new taxon is described as C. stipitata. We confirm the distant relationship of these taxa (C. apodocarpa, C. petrophila, and C. stipitata) to C. caespiticia, a species with stipitate or pseudopodetiate (vs. sessile) apothecia. A treatment of the North American apodetiate species of Cladonia including distribution maps, cited specimens, and illustrations is presented. A key to the taxa that includes unrelated, frequently sterile species of Cladonia found in eastern North America is also provided.

本研究针对北美无柄及表面无柄的石蕊属（Cladonia）物种分类系统进行修订，该类群物种均具有持久的鳞片状叶状体，具体涵盖C. apodocarpa、C. caespiticia与C. petrophila。研究结合形态学、化学及生态学数据，并针对内转录间隔区1（ITS1）、5.8S核糖体RNA基因（5.8S）及内转录间隔区2（ITS2）序列数据开展分子系统发育分析。
该研究方法的结果验证了该类群中部分已确立的分类学概念，同时对其余概念提出了质疑。被命名为C. apodocarpa的类群，经基于似然法与简约法的分子系统发育推断，结合形态学、化学及生态学特征，均得到充分支持。然而，针对“C. petrophila是否为独立单系类群，抑或C. apodocarpa嵌套于其中”这一问题，分子证据并未给出明确结论。此外，基于本研究使用的分子标记，未检测到C. petrophila产与不产富马原扁枝衣酸的化学宗之间存在系统发育结构。但C. petrophila作为分类单元，仍凭借其化学特征（即球松素的存在）、形态学及生态学特征得到充分支持。
本研究还描述了一个形态学与生态学特征均独具特色的新类群C. stipitata。本研究证实，上述类群（C. apodocarpa、C. petrophila及C. stipitata）与C. caespiticia的亲缘关系较远，后者具有具柄或假柄（而非无柄）的子囊盘。
本研究提供了北美无柄石蕊属物种的分类处理内容，包括分布地图、引证标本及形态图解。同时还编制了分类检索表，涵盖北美东部地区发现的亲缘关系较远且常为不育的石蕊属物种。