Parmelia sp.?

Parmelia sp.?

Observation - Parmelia sp.?. Description: Lichen (left) on an old oak branch. Overall form and net marks suggest P. sulcata but P. saxatilis (or something else?) seems possible. Went for P. sulcata as more common and, although rural, this location is close to busy roads, housing, some air pollu

Lichen (left) on an old oak branch. Overall form and "net" marks suggest P. sulcata but P. saxatilis (or something else?) seems possible. Went for P. sulcata as more common and, although rural, this location is close to busy roads, housing, some air pollution probable. Grateful for any suggestions.