Blackening of the veins of a cabbage
leaf following inoculation with the black rot pathogen, <em>Xanthomonas
campestris </em>pv. <em>campestris</em>.

Blackening of the veins of a cabbage leaf following inoculation with the black rot pathogen, Xanthomonas campestris pv. campestris.

Photo Source: Lindsey du Toit, Washington State University