Strumpshaw Fen Cribraria likely aurantiaca

5 July 2024

At Basecamp — on the log that we often find slime moulds and Artomyces pyxidatus (daughter’s 2023 mycological survey at the reserve) — I was captivated by groups of glossy yellowish green sporangia (I’m using the Danish Mycological Society’s colour chart).

A Google Lens search suggests that this slime mould is Cribraria aurantiaca and throws up wonderful photos by Barry Webb of slime moulds likely to be C. aurantiaca.

Some Google results state that the green sporangia are a “rare” form, however at the Buckinghamshire Fungus Group’s slime mould page (nearly half way down) there are some Barry Webb photos of C. aurantiaca from Burnham Beeches with a description that the “sporangia develop through green to blue then eventually ochre orange when mature”.

In The Myxomycetes of Britain and Ireland Bruce Ing states that the plasmodium of C. aurantiaca is a “bright leaf green” — on his blog Colin Purrington posts a photo of C. aurantiaca plasmodium that he found in 2017.

Cribraria likely aurantiaca – Basecamp
Strumpshaw Fen – 16th June 2024
Cribraria likely aurantiaca – Basecamp
Strumpshaw Fen – 16th June 2024
Cribraria likely aurantiaca – Basecamp
Strumpshaw Fen – 16th June 2024

Note the small group of white sporangia left of centre in the photo below.

Cribraria likely aurantiaca with small group of white sporangia left of centre
Basecamp – Strumpshaw Fen – 16th June 2024

Amongst the groups of green sporangia were scattered smaller groups of these white sporangia. On some of the white sporangia there were tiny brownish vinaceous droplets.

White sporangia amongst the Cribraria – Basecamp
Strumpshaw Fen – 16th June 2024

I was inclined to think that the white sporangia were a juvenile stage of C. aurantiaca — they were in and amongst the green sporangia groups and had a similar form but I can’t find any reference to C. aurantiaca having white sporangia.

Cribraria likely aurantiaca – Basecamp
Strumpshaw Fen – 16th June 2024