Microbotryum pustulatum on Bistorta vivipara. A Habit (3 Aug 1933, leg. A. Hagen, s.n., O, s.n.) B, C spores in LM, in median and surface view, respectively (3 Aug 1933, leg. A. Hagen, s.n., O, s.n.) D–F spores in SEM (C-F-102474) G distribution map. Scale bars: 0.5 cm (A); 10 µm (B, C); 5 µm (D–F); 500 km (G).