Didymodon tectorum

Ignatova, E. A., Fedosov, V. E., Kuznetsova, O. I., Fedorova, A. V. & Ignatov, M. S., 2024, On the genus Didymodon s. str. (Pottiaceae, Bryophyta) in Russia, Arctoa 33 (2), pp. 129-155 : 138

Didymodon tectorum

This species was never recorded for Russia. It was described from Shaanxi Province of China; according to Li et al. (2001), it is widely distributed in China and considered to be its endemic. However, Saito (1975) reported it from Japan and Zander & Ochyra (2001) discovered it in the USA. It is very similar to D. cordatus morphologically: both species possess strongly revolute leaf margins almost to the apex, papillose laminal cells and multicellular axillary gemmae. In the study of Jiménez et al. (2022), D. tectorum was found to be sister to D. imbricatus , and their mutual clade was sister to D. cordatus . In our analysis, one sequence (isolate OK3482) obtained from specimen from Altai Mts had much in common with D. tectorum (this species was found to be most similar by BLAST search); however, it was resolved not with D. tectorum but in a sister position to the mutual clade of D. tectorum + D. desertorum + D. imbricatus . Furthermore, morphologically it did not fit any of this species but was identical to the new species described here as D. baicalensis ; it needs additional study.