There is plenty of info out there… You should check Index Fungorum to see which names to look for:
http://www.speciesfungorum.org/...
And see the Pholiota, also Kuehneromyces has been seen as a section of Pholiota for many authors, so you can check Pholiota for North America info here:
http://www.mykoweb.com/Pholiota/index.html
And see the listing for Pholiota vernalis here:
http://www.mykoweb.com/...
There Smith and Hesler equate Agaricus vernalis and Agaricus lignicola, so they believe that these are the same species, and there isn’t a difference.
You can also see notes on the species here in MO, with two different obs. that have rather good notes:
http://mushroomobserver.org/63843
http://mushroomobserver.org/46639
That should be enough maybe?