Tiny black spots (conidioma pycnidia about 0.3mm) on both sides of the last year leaf of American Beech (Fagus grandifolia).
Conidia with 3(4) septa, measure in H2O
(17.5) 18.3 - 22.3 (24.1) × (2.3) 2.34 - 2.8 (2.9) µm
Q = (6.3) 6.8 - 9.2 (9.6) ; N = 25
Me = 21 × 2.6 µm ; Qe = 8.2