Lichtenberg figures - it marks left on certain materials after exposure to high voltage. These figures are ferns form and consist of branching electric charges. The spark discharge channels having a strong high temperature and pressure that deform the surface of the dielectric, capturing her Lichtenberg figures.
When a person gets struck by lightning, these figures may appear on the body in a few hours or even days. It is believed that this is caused by rupture of blood vessels under the skin. Medical experts are of the presence of Lichtenberg figures to determine the cause of death.
These figures are also called "Flowers lightning».
via factroom.ru