scots pine blister rust cronartium flaccidum, a heteroecious rust fungus on a branch

agriculture background blister cronartium damage damaged danger destruction detail disease diseased diseases environment flaccidum flora fungi fungus fuscum garden green growth gymnosporangium illness image infected infection infestation micro mold mould nature needles orange outdoor parasite pathogen pathogenic pathology pest phytopathology plant removal rust rusty surface tree unhealthy