Microbotryum bistortarum on Bistorta vivipara. A Habit (leg. A. Hagen, s.n., O, s.n.) B, C spores in LM, in median and surface view, respectively (B. Hanfgarn & B. Jacobsen, no. 553, C-Greenland herb., s.n.) D–F spores in SEM (D, E J. Feilberg, no. 1189, C-Greenland herb., s.n.; F B. Hanfgarn & B. Jacobsen, no. 553, C-Greenland herb., s.n.) G distribution map. Scale bars: 0.5 cm (A); 10 µm (B, C); 5 µm (D–F); 500 km (G).