1. K. I. Flatberg, K. Hassel (https://orcid.org/0000-0002-1906-8166) ✉ () and T. Prestø, Dept of Natural History, NTNU Univ. Museum, Norwegian Univ. of Science and Technology, Trondheim, Norway.
2. M. O. Kyrkjeeide, Norwegian Inst. for Nature Research, Trondheim, Norway.
3. A. J. Shaw, Dept of Biology, L.E. Anderson Bryophyte Herbarium, Duke Univ., Durham, NC, USA.
4. T. Ahti, Botany Dept, Finnish Museum of Natural History, Univ. of Helsinki, Helsinki, Finland.