Winged Elm--What's this: elm mycorrhyzia or rotting wood fungus?

[Oliver Muscio]

I had to repot a winged elm (ulmus alata) because its grow-box was falling apart. After removing the tree and soil from the box, I found each of the holes in the bottom was plugged with a white fungal growth (see white discs below). There were also streaks of this growth through the soil (ca. 80%Mule Mix, 20% pine bark) and in the joints of the box. The tree had seemed to grow well during the season, and the roots look healthy. Just wondering: is this an elm mycorrhyzia or a fungus growing or decomposing box wood?

 

[0soyoung]

Looks to me that it is a fungus that was consuming the box.

 

[edprocoat]

Looks to me that it is a fungus that was consuming the box.

A box eating fungus ! STD's these days are horrifying.

ed

 

[Oliver Muscio]

Looks to me that it is a fungus that was consuming the box.

Probably. The interior of the box was very punky.
Oliver

 

[Mellow Mullet]

I agree with the others. I have several winged elms, as does my father, and we have not noticed anything like this. The white fungus looks a lot like the kind of fungus that forms on firewood that gets wet and starts to decompose, so it could be what was decomposing the box, as others have said.

 

[NewWorldBonsai]

That mycelium is feeding on the box, your elm is fine.