Mushroom

While walking through town today, I was scanning the cottonwood trees for birds.  I saw only crows, pigeons and house sparrows and was grumbling over the lack of a new species to put on my blog when I saw some mushrooms perched on top of a pruned tree. 

The first photo is zoomed as far as I could make it, because I wanted to try to identify what mushroom could possibly be growing in the middle of January.  In the following picture, you can just see the mushrooms perched in the top center.   The last picture is a mushroom growing out of the cut branch on the left side of the cottonwood.

I know very little about identifying mushrooms, but my best guess is that these are a type of wine cap mushroom, Stropharia rugosoannulata.  I may be completely wrong here.  Besides not knowing much about mushroom species, I couldn't get close enough to these specimens to see all the details.  So all I'm saying is, don't hold me to it and don't even think about eating them.

This blog post is going to be total guess work.   I'm suspecting the fungi spores got into the wood during or soon after the pruning of this tree.  Were the spores on the chain saw?  Can the gusty Wyoming wind blow spores that high?  Are these mushrooms still alive after the single digit temps of the other night?  If so, are they damaging the cottonwood?   Or is the tree already dead?  I won't know the answer to the last question until spring.   As for the other questions, Google and Wikipedia aren't helping too much this time.  This experience obviously reveals a great gap in my nature knowledge and makes me predict that I will be noticing and photographing--and hopefully learning more about--a lot more mushrooms this year.