Konstantinova, N.A., A.A. Vilnet & E.D. Lapshina. 2026. New species of liverwort from Yakutia (Russian Arctic): when striking morphological differences are not supported from DNA

Arctoa (2026) 35: 21–36

doi: 10.15298/arctoa.35.02

A new liverwort species Rudolgaea aenigmatica is described from Yakutia based on a combination of striking morphological features, particularly very narrow, abaxially concave, undulate leaves with unevenly and irregularly curved margins, deep sinuses, lobes sharply tapering into a long, more or less narrow, sometimes incurved apex, margins often with long teeth, teeth-like lobes or cilia near the base that strikingly differs the species from all known liverworts. Molecular phylogenetic study resolved it in one clade with Rudolgaea borealis. The nucleotide sequences of two nuclear and five chloroplast DNA markers reveal the identity between R. borealis and the newly described species. ISSR analysis provides common bands composition for both species from 11 primers. At present, both species do not obtain molecular differentiation. The described species occupies similar habitats and is found in the same plant communities as R. borealis. Such obvious morphological differences in the absence of clear molecular and ecological differentiation have been described for liverworts for the first time, and at this stage of knowledge we cannot find an explanation for this.