With fungi, you sometimes just have to stare at them blankly for a while and then a picture suddenly forms in your mind and a possible identification suggests itself. I went through and rejected quite a few possibilities for this one before I hit on Cortinarius. When I got back to the books it was clearly one of the Dermocybe group, and the yellow gills indicate that it's Cortinarius croceifolius (now Cortinarius malicorius) - a Salix associate, which would fit perfectly.
The dotted margin for this one points us towards Hypholoma marginatum:
This little group of Collybia dryophila caught my eye: