Kuehneromyces mutabilis (sheathed woodtuft) vs Galerina marginata (funeral bell) ☠️
One edible, one deadly, and looking quite similar! Both grow on dead wood, have crowded ochraceous cream gills that are adnate or slightly decurrent, gills turn brown as spores drop, have tan caps that start off convex, tough brown stipes, and a small annulus (skirt) that can easily detach or degrade.
Both have hygrophanous caps (where colour changes as they absorb water or dry out - but in a different manner).
I found all of these on dead hardwood, though Kuehneromyces is said to prefer birch, and Galerina conifers, there is overlap.
Kuehneromyces mutabilis has a cap that is almost always lighter in the centre as it dries out giving a two tone appearance - depending on age and wetness how obvious this is can vary and this is one of the most obvious differences. The cap flattens out and usually retain an umbo. Under the annulus, the stipe is a plainer brown. It’s common and often appears in large groups. I found these on birch and beech. It’s edible, but not often collected as it can be hard to distinguish, and isn’t super highly rated anyway.
Galerina marginata has a cap that is usually lighter at the margin as it dries out, rather than the centre and is a bit striate, and flattens out without an umbo. It has a silvery streaky stipe under the annulus. I found these on beech. It’s a little more uncommon that K mutabilis. It contains amatoxins, which are deadly if consumed.
