leaf of populus tremula or common aspen infected with gloeosporium tremulae

aspen broken common cylindrosporella damage damaged disease diseased european fungi fungus gloeosporium green infected invasive leaf leptothyrium melampsora parasite pathogen pathogenic pathology pest phytopathology plant poplar populnea populus puccinia pucciniales rust spot spots titaeosporina tremula tremulae