Oyster growing on a birch... never seen it before

[flipjargendy]

A friend of mine sent me a photo of these little guys to ask if I could ID them. I've been looking online a bit for oysters or shelf mushrooms that grow on birch trees... I keep going back to Pleurotus ostreatus but its hard to say. The ones in the photo are pretty young still and I've never seen anything but Piptoporus betulinus (birch polypore) growing on Birch in our area. This one is throwing me a bit. Any help is appreciated.

The photo was taken in northern MN.

[Sherwood]

Probably gonna need more detailed pics of this. 

[Old Oak]

Sure it wasn't an aspen tree? I trust your ID skills but don't know how good with trees your friend is. Aspen could be mistaken for birch. They definitely grow in aspen. 

[flipjargendy]

@Sherwood, I agree. I don't think its too big a deal though. I think I'll pass on the ID on this one. He sent this to me from work and probably won't be getting more pics.

@Old Oak, thats what I was wondering. Even with the poor photo, it doesn't look like a birch to me. But that's what he said it is and he's an outdoorsman... I'd hope he knows the difference between a birch and an aspen lol.

[rob]

Looks like aspen. Note the vertical splits. if it were birch there would be bark curling along the split lines.

[Dave W]

Difficult to tell the type of tree. But as has been said, apsen and birch are easily confused, especially in a spot where both are found. Mushrooms look like Pleurotus. A common springtime species is P. populinus, which always grows on aspen. 

[flipjargendy]

Thanks @Dave W thats what they look like to me. Aspen and Birch are often mixed in our area. I'm guessing he was just looking at it wrong. I find these mushrooms all the time but have never seen them with what appears to be a stem. I've just never been lucky enough to find them that young :-)