Discrete cankers first appear on young trees as brown, slightly sunken areas in the smooth bark of branches and trunks. These cankers are circular to oval or irregular in shape. Frequently, as the canker gradually enlarges, affected stems are girdled and killed. Twigs commonly die without the formation of typical lesions. Vertical cracks within the lesion and along the canker margins often occur in the bark. As the cankers enlarge the diseased outer bark may become black, brown, gray, reddish brown, or yellow and sunken depending on the host species and stage of disease development. The inner bark turns black and sometimes gives off a foul salty odor. The sapwood appears reddish brown to black and water-soaked. Cankers frequently start at wounds or branch stubs or at the base of dead twigs. Cankers on large stems with thick, rough bark may be imperceptible except for yellowish to reddish brown spore horns (sticky, thread-like masses of spores) protruding from bark fissures. Severely infected trees usually die branch by branch often producing sprouts at the base of the trunk which also become infected and die.