Konstantinova, N.A., A.A. Vilnet, D.G. Long & Y.S. Mamontov. 2025. Hidden diversity and the treatment of Jungermannia pumila s.l. with description of a new subspecies from the Russian Far East

Arctoa (2025) 34: 133–151

doi: 10.15298/arctoa.34.11

An integrative study of the Jungermannia pumila complex in the Northern Palearctic – from Svalbard to the Caucasus and from the British Isles to Kamchatka and Kuril Islands, including specimens collected near the type localities of the taxa showed molecular genetic divergence into three closely related subclades of the same major clade. The major clade is treated here as J. pumila s.l. and the obtained subclades are considered as subspecies. One subclade is formed by specimens from the British Isles and Central Europe; these specimens morphologically are in good agreement with J. pumila subsp. pumila. The second subclade consists of specimens from the northern regions and upper belts of the mountains of Europe and Asia. Some of these specimens morphologically correspond to J. pumila subsp. polaris. The third subclade includes specimens from the southern regions of the Russian Far East and the mountains of South Siberia. We describe them as a new subspecies J. pumila subsp. orientalis. Morphological variability of the specimens is significant and overlaps between the subclades. Taking into account comparatively low molecular genetic divergence between the subclades, it may be considered that the discussed three taxa are in the process of diversification and their morphological differentiation is not complete. Therefore, we treat them as subspecies. The variability of individual morphological features and the ecology and distribution of the discussed subspecies were examined.