Six species of the genus Didymodon with caducous leaf apices are reported from Russia (Siberia) based on collections from KRF, IRK, MHA, LE. The specimens previously identified as D. rigidulus and D. johansenii (Williams) Crum are found to represent also D. anserinocapitatus (X.-j. Li) Zand., D. hedysariformis T. Otn., D. gaochienii B.C. Tan & Y. Jia, and a new species Didymodon murrayeae, T. Otn. sp. nov. Diagnostic characters and illustrations are provided for the taxa. For D. hedysariformis and D. johansenii sporophytes are found, for D. gaochienii and D.murrayae perichaetia are also indicated.