hi
I would dry the specimen and label the packet it as c.f.
versutus; I think the only other (remote) possibility is
Crepidotus epibryus which has been named and moved from genus to genus on numerous occasions (= among others "
Crepidotus herbarum", "
Pleurotellus graminicola"); this has characteristically narrow spores rather like yours and would be something you would expect on stems like those you found this on (but the spores are never wider than 3.5 microns)
epibryus is synonymised with
Crepidotus pubescens in the sense of Kühner & Romagnesi (1953);
versutus is synonymised with
Crepidotus pubescens in the sense of Watling and Gregory (1989) so you can see the confusion
-
Crepidotus pubescens in the sense of Pearson (1949) is
Crepidotus luteolus - but your fungus is not that
cheers
Chris