male hand holding red maple leaf diseased of powdery mildew, fungal disease of maple trees. pathogenic fungi, phytopathology,

acer botany branch concept deciduous disease diseased diseases flora floral foliage fungal fungi green hand holding illness infected leaf leaves male maple mealy mildew mushroom nature norway parasite pathogen pathogenic pathology phytopathology plant platanoides powdery problem red sawadaea spot spots struck tree trees tulasnei uncinula white