Likely Didymium squamulosum slime mould – plasmodium to sporangia at Strumpshaw Fen – Winter 2025/26

At the same stump where we found what might have been Physarum psittacinum, another slime mould first for us – Didymium squamulosum (likely).

20th December 2025

We spotted a large white patch from afar and as we approached – it was a large sporulating plasmodium on another part of the decaying stump as the possible Physarum psittacinum.

The photos below show the plasmodium forming clusters of sporangia.

These two photos below show an area of the plasmodium that is still a little amorphous with the globular sporangia beginning to form.

We returned in the evening and the daughter spotted some maturing sporangia that I had missed in the morning – further along the stump, left of the white plasmodium.

But were these sporangia the same slime mould species as the white plasmodium...?

21st December 2025

This next photo shows an intricate network of plasmodial veins.

22nd December 2025

Two days on from when we first spotted the plasmodium, a distinct maturing and colour change of the sporangia was evident – from the white of the earlier sporulating stage to brownish vinaceous (younger) to light bluish grey (older).

Clearly, this is the same species as the adjacent mature sporangia from the first day.

Notice the out of focus younger white sporangia in the photo below.

23nd December 2026

The next day the sporangia were no longer moist and had taken on a matt appearance – ranging from light bluish grey to ash grey.

A week later, the sporangia were all dehiscing, revealing their brown spore masses. The peridia had all become a pale bluish grey.