Identification: What is this plant/fungus

Can anyone please tell me what kind of fungus or mushroom this is?
It is growing on my lawn on top of a root from a cut down silver poplar.
Would appreciate an identification. thanks

 

A photo of the underside would help.

 

Hope this underside picture helps. Tried not to damage it, trying to see how
big it will get. It is really soft and spongy like.

 

Looks like a Pleurotus to me. I would suggest P. populinum because it is assosiated with poplar.

 

Thank you so much. That type must grow in a lot of different ways, couldn't find
a picture on the internet just like it.
Was wondering if I picked it and brought it in, would
it dry nicely to use as a decorative piece? When the snow flies it will die.

 

1. is it growing on wood or just on grass?

2. it'll dry out pretty quick, so I wouldn't take it inside. It should come back in future years, though.

 

The dead tree root is close to the surface underground with grass on top of it. The plant is growing on that grass. Guess I will just leave it be and see what happens
in the spring. Never realized there are so many different kinds of these things until
I checked out the internet. Interesting how, where and why they grow.

 

Maybe a Pleurotus sp.

American fungi, unknowed for me ;)

Nico