eltio

How about Leucocoprinus birnbaumii for the yellow one?

Thanks. I didn’t know that.

How about Russula cyanoxantha v. pelteraui?

It’s difficult to tell from your photo what we are looking at. I think it’s something growing on a tree trunk. I can’t see any familiar structures, so it’s possible that it’s too old to tell. Adding close-ups is a good idea.

Would Gymnosporangium be a possibility?

I’ve never seen it grow in clusters like that. Is it typical?

I’m sort of sorry I ever mentioned Armillaria now, but the scaled surface of the lower fb and the general appearance of the stipe and ring still have a familiar look to me. I’d agree on size and timing of course. However, where is your evidence for this being brown spored? Do these photos really say Galerina or Tubaria to you? I still think it’s a puzzle.