Injured plants show a darkened area from the ground upward along one side of the stalk into the midribs of the leaves. Affected portions of the veins turn black and shrink, giving the leaf a puckered or gathered appearance. The roots do not show evidence of injury. If a stalk is split after it has dried somewhat. It may be hollow, or the pith may be separated into colorless discks with a layered effect. The pith remains white which differentiates lightning damage from black shank. Some plants in the center of the strike area may be killed, with less severe injury in scattered plants. Lightning injury is often mistaken for disease damage.