See:
Poplar (Populus spp.) - Leaf and Shoot Blight
Note Venturia macularis (formerly V. tremulae) is found on aspen (P. tremuloides).
Many leaves with necrotic areas due to Venturia infection.
Jay W. Pscheidt.
Shoot blight due to Pseudomonas syringae on aspen.
Larry Moore, 1982.
See:
Poplar (Populus spp.) - Leaf and Shoot Blight
Note Venturia macularis (formerly V. tremulae) is found on aspen (P. tremuloides).