ID for 'fungal caviar'

[ceridwen]

Hi. I would be grateful for help with
Found in a rotten tree stump (not identified) on Hampstead Heath, London, on Jan. 31st.
These tiny pinheads were all over the damp vertical surface of the rotten timber inside the hollow stump. I broke off this small piece which is 7cm across the widest part. The nearest resemblance I have found online is to Rhizosphaera kalkhoffii, which infects spruce needles. Alternatively, could it be the fruiting bodies of an underlying slime mould (which was not detectable in situ).
Looking forward to expert opinions!

[mollisia]

Hello,

it is hard to see, whether those pinheads are stalked or not. It seems that yes, what would be a hint that it is a myxomycete. Then they should have been very soft. If they are just balls without any stalk, then they should have been hard and are some pyrenomycetes. May be a Leptosphaeria doliorum or a Rosellinia aquilina.

best regards,
Andreas

[ceridwen]

Thanks. The pinheads are hard (but crushable) and have survived since I picked them on Sunday without any visible change. They do have stalks, and look like minute elderberries, standing straight up.

[flaxton]

Try Metatrichia floriformis and see how that matches.

Mal

[ceridwen]

That looks like it - although none of the little black spore-producing bodies in my specimen had/have split open in the flower-form they are named for. Many thanks!