In sphagnum in a peatland
Cap strongly conical. Gill edges at least partially orange. Mycena citrinomarginata is similar but with a paler cap that may be distinctly yellow.
M. aurantiomarginata is apparently only known from the western US, growing under conifers. The weak color of the gills and the habitat suggest that it's likely not M. aurantiomarginata, but that is the closest match I can find right now
More of that obscure gall occurring on Physocarpus opulifolius. This bud-gall was sometimes accompanied by globular leaf galls occurring in pairs. Anyone have any information on these?