Kretzschmaria deusta (Ustulina deusta)

Common host(s)                     Beech and other broadleaved trees including Oak, Lime, and Maple.

Colonisation strategy             Mainly enters via injuries to the base of the stem or large roots.

Symptoms                              The perennial fruiting bodies produced by this fungus appear as a black, lumpy, charcoal like crust that turns to dust when crushed. They form a layer which can be extensive in size and appear as a layer of tar close to the soil and are commonly found on buttress roots, around the base of trunks They persist for several years.

Type of rot                             Initial Soft rot which may develop a white rot in advanced stages.

Part(s) of tree affected          Lower stem buttresses and principal roots.

Significance                            The development of the ‘Soft rot’ can lead to a catastrophic brittle failure. Such a decay type can cause failure of the tree with little or no warning. This fungus is considered a particularly dangerous type of decay fungus due to the type of decay it produces and because the fruiting bodies are sometimes difficult to spot.

No controls available.

All photographs are reproduced by kind permission of the Arboricultural Information Exchange