Eiffel Tower bracket
Oak – namely Quercus robur.
Other oak species, sweet chestnut.
Generally isolated to the stem base – in between buttresses / stem flutes. Rarely observed up the stem, to heights of 3-4m, for very large trees. Restricted generally to mature trees.
Annual. Found growing most often singularly – rarely in tiers. A tan brown upper surface from inception clad with water droplets (see photo a,b). Pore surface white. Flesh and tube layer chocolate-coffee brown. Very tough and woody. Can become very large, in some cases. Blackens-off in autumn and often remains attached to host either wholly or partly.
Associated with a selective white rot and linked to extensive buttressing in mature oaks (‘bottle butt’). Decay considered to be very slow though hollowing does ensue. Host trees can thus persist with this fungus by developing sound buttresses. Failure rarely observed on Quercus robur. Where no buttressing exists on the host tree, failure should be more of a concern. Investigations into stem hollowness / tree stability may need to be considered.