Dryad’s saddle fungus

[Rob2025]

Fungus appeared this year on twin stem sycamore tree. Growing out of top of old cut wound. Given left hand stem on picture is leaning at appropriate 20 degrees at base is this a problem it terms of the tree becoming unsafe. Tree is approximately 25m tall.

[Ledburyjosh]

From the TMA webpage:

 

'Associated with a selective white rot of the wood. Causes cavity formation. When found locally, decay is more likely restricted to this area. Multiple brackets over larger areas suggests widespread dysfunction. Associated with the decline of trees, when found in abundance. Associated with stem and limb failure – notably in species with weaker wood qualities (horse chestnut, poplar).'

 

I'd suggest at present it's localised in the dysfunctional wood from where the fruiting body is emerging. Something to keep an eye on though as any significant decay at the base will increase likelihood of failure.