Fire blight is a disease caused by the bacterium Erwinia amylovora .
It infects pears, apples and quince as well as ornamental plants of the Roseaceae family including cotoneaster, hawthorn and pyracantha. Blossoms are usually infected first and have a water soaked appearance. Eventually the blossoms will wilt, shrivel and turn black. The most characteristic symptoms are blackening of leaves, shoots and, in severe cases, branches. A sticky ooze, which contains millions of bacteria, will seep from the infected area.