Ganoderma applanatum-Artist's fungus on white willow

Our beautiful willows are infected by Ganoderma applanatum- bracket fungus.

The old weeping willows and white willows on the banks of our river are a symbol of the town. On my last walk I discovered that two of a group of five white willows are infected.

While Ganoderma applanatum-shelf fungus is a useful decomposer of logs and stumps but it also lives as a parasite on living trees, causing butt rot.

This fungus is a common cause of decay and death of many types of trees, especially maples, alders, birches, beech, apple, poplars, cherry, plum, oaks, willows, and elm.

The fungus attacks the tree trunk's thickest part, at the base, near the soil line.
It may take several years but finally the fungus kills the host tree.
There is no treatment or control once a tree is infected, it is only a matter of time until it dies.

Artist's conk, on its other name, produces very distinctive, shelf-like brackets grouped in several horizontal rows. Often there is only one bracket produced on an infected tree. The fungus is a perennial and grows for 5 to 10 years, reaching over 50 cm across.
Ganoderma applanatum produces the largest brackets of any fungus.

They are rough and have a woody feel. Their upper surfaces are dark reddish-brown to black, with a creamy-white margin.

The underside of the bracket is white to light yellow but turns brown when scratched or bruised.
Because of this property of the conk, artists use it as a natural medium for drawing and painting, hence the names Artist's conk and Artist's fungus. You can carve writing or pictures in it and the drawing naturally darkens.

They are attached to the tree over most of their width and very hard to detach. I intended to bring one home to paint on it but these are too small and already dirty, as you can see in the picture above.

I just hope the other willows will not be infested by the the mycelium of the fungus. This place will never look the same without the old weeping willows.

See more tree fungus pictures at this other post.