ABSTRACT Introduction. Although Madagascar is known for its unique fauna and vascular flora, the country’s bryophyte flora in contrast is understudied and under collected. Arising from a bryophyte collecting expedition undertaken in May–June 2016, this paper describes a new species of simple thalloid liverwort, Fossombronia isaloensis, from Madagascar. Methods. Morphological traits across specimens were reviewed and compared with related species. DNA sequence data from rbcL, rps4 and trnL-trnF was obtained from 7 accessions of Fossombronia from Madagascar and 18 other named species of the genus and used to produce a plastid-based phylogeny. Results. DNA sequence data show that Fossombronia isaloensis is not closely related to any other Fossombronia taxon sampled for this study. A description and diagnosis is provided and a type specimen designated for the new species. Conclusions. The bryophyte flora of Madagascar urgently deserves further inventory and taxonomic investigation.

中文翻译：

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Fossombronia isaloensis Cargill & DACallaghan，一种来自马达加斯加南部砂岩地块的新地衣

摘要介绍。尽管马达加斯加以其独特的动植物群和维管植物群而闻名，但相比之下，该国的苔藓植物群却没有得到充分的研究和收集。源于 2016 年 5 月至 6 月进行的苔藓植物采集考察，本文描述了来自马达加斯加的一个新种的简单类地苔，Fossombronia isaloensis。方法。回顾了标本的形态特征并与相关物种进行了比较。来自 rbcL、rps4 和 trnL-trnF 的 DNA 序列数据是从 7 个来自马达加斯加的 Fossombronia 和 18 个其他命名物种中获得的，并用于产生基于质体的系统发育。结果。DNA 序列数据显示 Fossombronia isaloensis 与本研究采样的任何其他 Fossombronia 分类群没有密切关系。提供了描述和诊断以及为新物种指定的模式标本。结论。马达加斯加的苔藓植物群迫切需要进一步的清单和分类调查。