Fungus Identification on Oak Tree

[Hcrum87hc]

I have a large oak tree in my backyard that has three fairly large spongy fungus growths growing near the base. I noticed one of the growths last year. It eventually turned black and kind of hardened and shriveled up a bit. I was hoping to get a general idea of what it is and what to expect going forward. Thanks in advance.

 

[JeffGu]

Looks like Ganoderma or Inonotus fungus (root rot) to me. If so, by the time you notice the annual fruiting bodies, the decay in the root flare and lower trunk is pretty much too extensive to treat. Usually, removal is recommended. The fungus infects injuries to the root flare and lower trunk... most commonly caused from lawnmowers and weedwhackers.

You really need to have someone with mycology expertise identify the fungus involved. Sometimes local Natural Resource Districts, nurseries, etc. can help you to identify the specific fungus and make recommendations.

 

[ATH]

Mycology is probably the area I need the most study in (I certainly find myself in the books looking up answers more with fungi than other ailments...). However, (based on the book...), I agree it looks like Inonotus - which the book Wood Decay Fungi) also says "Sometimes an indicator of extensive root and butt decay and reason for immediate removal".

Have it evaluated onsite. There will likely be decay, but how extensive? It is in its last days...but suggesting whether that needs to come out today or be re-evaluated in a few years is better done with a site visit. Or if it is in the middle of a big yard where nobody spends any time and it can't hit anything when it falls, maybe you just leave it stand?

 

[JeffGu]

Mycology is probably the area I need the most study in...

You and me, both. I just try to remember the ones I see the most and are bad news. Oh, and these...

 

[Hcrum87hc]

Thanks fellas. Based on my brief internet research, I had assumed it was of the Inonotus variety. I think I saw it was also called oak bracket or something.

The tree is at the back of our lot, but we only live on .25 of an acre, and if it falls towards the house, it would do extensive damage. I know it’ll have to come down soon, but how soon is the question. I have left a message with a local certified arborist to schedule an evaluation and hopefully get a relative timeline.

From my layman’s eyes, the rest of the tree appears healthy. It’s full of leaves and just survived some 30-40 mph gusts from tropical storm Irma, but I won’t pretend it didn’t scare me lying in bed that night.

 

[ATH]

It can be healthy and structurally insufficient at the same time, so don't be fooled by a full green canopy.

 

[Jason Douglas]

Fungal ID from a pic us quite difficult but I would also lean towards Inontus. Field ID and assesment is the way to go.

 

[Hcrum87hc]

Thank all. Based on what I’ve read here and elsewhere, I’m going to go ahead and remove the tree. I don’t have an attachment to it, and if it were to fall, it’ll go right through the back of my roof. I’d rather not risk it.

 

[earlthegoat2]

I had to just remove a cedar tree in my yard. We have been there for 5 years and the tree was never exactly vigorous. I pruned it to raise the canopy a little at a time over the years and the pruning cuts never started to heal over. Then I saw armillaria a few months ago all around it. I got closer in and dug around the root flare and all around the circumference about 3/4 of it was just powdery rotted wood.

I removed it and it had rot all the way to the top of the main trunk. At the base there was only 1/2 solid wood still there. It was leaning heavy toward the house so that is what prompted removal. At a glance, there appeared nothing wrong with it. Full green canopy and no bark problems. Over time though, you just knew something was up.