The frequent rains this autumn have prompted at least some fungi, sleepy over the last few years, to present with fruiting bodies. Yesterday I ran across these bright little ascomycetes, emerging from a very rotten treefall in patches. The largest of them is only a half centimeter across.



Notice how the emergences are confined to the inner portion of the fallen tree. The feeding mass of mycelium seems to be uninterested in the cork part of the bark, which has fallen away in places, to reveal the bright yellow ascocarps. Instead it goes after the inner xylem.

It’s a good thing they were so easy to find on the internet, since they weren’t listed in my Audubon at all. They’re Bisporella citrina, lemon drops or yellow fairy cups, and that’s a link to some very nice photographs of the fungus, as well as a vague lookalike.

Notice how there seem to be various stages of shapes here. The youngest emergences seem to have a rounded top, which begins to dimple in. Eventually that dimple achieves the cup shape that’s typical of many ascomycetes.

But what are those grayish cups?

The photographs often yield details that my eyes don’t catch. This cut catches a few yellow cups in transition to a gray stage, which may be the sporulating stage, or may be senescent fruiting bodies. Or both. At any rate the gray cups seem to be the same species, and not a different one.

Not that there *couldn't* be a different species that commonly grows alongside this one. Blue stain fungus, Chlorociboria aeruginescens, as the very nice combo photo at that link shows. I’ll have to revisit and see if that’s the case here.