and I just wanted to state that one has to be a clairvoyant or soothsayer to tell it without taking a look at the spores :)
Some years ago I got my Crepidotus finds re-checked and about 40 % proved me wrong. I am very carefully in determining Crepidoti since. But the main reason was I was not experienced enough in microscopy to properly distinguish the sculpturation of the spores and to fathom the diversity of the spore sizes as well as I had a lack of good literature. With a few good monographies at least at a small scale this has changed and I even developed a small faible for the genus altho usually I am not into Agaricales that much.

More info here, with details and photos of spores too:

http://mushroomobserver.org/obs/4481
http://mushroomobserver.org/obs/5601

It is the ellipsoid, finely punctate spores (I believe, might have to check that…), with the white fibrous cap surface, and non-hygrophanous. There are actually a bunch of Crepidotus with this, from the Smith and Hesler monograph say (it was Smith and Hesler for that one, yes?), but they were synonymized in the Italian Crepidotus book from 2009, by… I forget his name right now… but it is good book.

I used a different name in the past, I forget what, but I moved to the new name after getting that book. There are other white Crepidotus out there, but I believe in California, not with the ellipsoid finely punctate spores.

Haven’t seen this name before, but I found a Crepidotus similar to this up in Mendocino.