What is this?

[Donnie]

Burnt a bit of this in my log burner, has to sit inside a good while to dry out now as it's like a sponge. Wondering what it even is. 
 

Absolute pain in the arse to split as well with a maul. 

[MrNick]

Looks like rotten wood, hard to identify, any bark or split wood may help

Guess1 Ash

[Timtree]

Looks bit like Hornbeam?

[s.varty]

Well seasoned oak ?

 

[Dan Maynard]

Sharp nobbly bits where the bark has fallen off, went rotten as left in rings, looks like poplar to me.

[spudulike]

Just from the sponge and difficult to split description, it has to be willow! It meets both of these from past experience. 

[Stubby]

Pop .

[Macpherson]

What ever it is, rotten wood will never burn well as most the calories have been consumed by the fungi, and if burnt it will probably smell bad as well, once the fungi gets a hold it's unstoppable imo, sorry to say... cheers.

Edited December 29, 2022 by Macpherson

[scbk]

If I was going to guess, the 4 larger rounds are rotten beech, and the smaller piece on top is elm. The vertical piece on the left with the ivy is something else.

 

 

These threads are always pointless as we never get to find out the real answer 

[Dan Maynard]

I can believe the big rings are beech, thought it looked like pop bark on the left. I've got some half rotted beech, soaks water like a sponge.

 

You're right though, how will we ever know we got it right?