got me stumped

[Charles]

this tree cell structure is very similar to a beech or dogwood and the wood color is the same, light to dark brown but I can't match the bark. Grows in around central Ontario. I am trying to get a leaf from the guy who gave me this wood

 

 
Any help would be appreciated

[Southside]

The bark reminds me of Gray Birch, but I never sawed one so no idea what the lumber looks like. 

[KEC]

The wood looks a lot like Black Walnut, but the bark has me baffled.

[btulloh]

I think Southside is right. I've seen birch tat looked like that, but no idea what kind of birch it was. The grain is very birchy. 

[low_48]

White poplar or silver-leafed poplar has that kind of marking in the bark, but not seen heartwood that color.

[Charles]

I am pretty sure it's yellow birch . I got a picture of the cell structure of yellow birch from Bruce Holdley's book on identifying wood and compared to my sample it looks the same 

Thanks for the help

[KEC]

I still don't know what this is, but not like any birch to me. Yellow Birch wood looks a lot like Sugar Maple wood. I'm also particularly puzzled by the bark.