Added on 31/12/2011Fungi

Kretzschmaria deusta


Formally known as Ustulina deusta.



Common on Beech (Fagus sylvatica) and other broadleaved / coniferous trees including Oak (Quercus), Lime (Tilia), and Maple (Acer).
This fungus is parasitic, living within and feeding upon the heart wood of its host tree, it creates the fruiting bodies as part of its reproduction process. It tends to manifest close to the soil and is commonly found on buttress roots, around the base of trunks and on old stumps.
The fungus produces two types of fruiting body. The first type is the immature fruiting body which consists of a white/grey flat layer. The second type is the mature body which appears as small rounded black lumps that have a charcoal, crusty consistency. They form a layer which can be extensive in size and appear as a layer of tar.
They persist for several years.
The black fruiting bodies produce the fungal spores within chambers. The spores are released into the air so they can travel and infect further trees thus completing the reproductive cycle.
This fungus has the ability to penetrate deep into the centre of large trees. It produces a heart rot which can leave the decayed wood in a brittle condition which can be deceptive if probing the surface of the wood for soft decay. 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. Infections should be inspected and monitored by an arboriculturist who can assess the risk of failure and recommend any necessary action


Photographs by Terry Merchant. 2004


Mature Beech adjacent to a country lane.

The co-dominant stems are splitting apart, with one stem weighted towards the lane. The fork was filled with leaves and aerial roots. The cracking extends to the base of the tree buttressing on both sides of the compression fork. Assessed as an increasing risk of the 50cm stem falling across the lane so recommended removal of tree. Tree failed before contractors reached it. Interesting to see presence of Ustulina, not visible until fork failed.




Photographs by Terry Merchant. 2004


Beech tree

Located within a woodland adjacent to the Foresters Arms, Broseley. Early-mature Beech tree standing within 2m and weighted towards, a public road. Visible evidence of root and stem decay fungi 'Kretzschmaria deusta ' between buttressing on east side of the stem. The presence of the charcoal-like mature fruiting bodies indicates an advanced state of internal decay in both roots and the central stem. Recommendation was to remove the tree as a high priority.
February 2004. This tree was felled. The white horizontal strip at 9.00 o'clock in the felled stem (see green arrows), marks the location of the fruiting body. Less than 20% of the stem wood remains intact.




Photographs by Andy Smith. 2004


Lime Tree

This Lime collapsed into an adjacent graveyard. As well as having been cut by footpath extensions over the years the lime was also suffering from 'Kretzschmaria'. The fungi was not very visible at ground level but the effects were dramatic!

I have not seen a decay pattern such as this before in Lime, very cubic in outcome. Not a lot of soft rot but the timber was dead and had the black colouring as you can see.











Please Note: Many Fungi are toxic and individual reactions to them vary widely. Do not touch or eat fungi unless you have accurately identified them. The AIE can not accept any legal responsibility or liability for errors in identification or for individual reactions to the consumption of fungi.