canker stain of plane
(Ceratocystis fimbriata forma platani)
A wilt disease of planes (Platanus spp.), sometimes called plane wilt. It is thought to originate in eastern North America and is fatal to P.orientalis and London plane. The disease causes blackish lens-shaped cankers, sometimes surrounding the initial infection site, dark discoloration of the sapwood and sudden wilt symptoms. Part of the crown is killed first, while the death of a large tree may take some years. C. platani was detected in Italy in the mid-20thC. Its spread was initially slow but appears to have accelerated. In 2006 the disease was identified in the 42,000 plane trees lining France’s Canal du Midi (a World Heritage Site).