Likely Heterotrichia ferruginea slime mould at Strumpshaw Fen – Winter 2025/26

22nd December 2025

Following on from the post about the likely Heterotrichia ferruginea slime mould we found at the allotment — later that day we visited Strumpshaw Fen and, at the fallen high stump in its exposed root crown, we spotted numerous groups of crowded sporangia with flesh-pink sporothecae 🤯

At first glance, it would be easy to mistake these for Hemitrichia decipiens — which is exactly what I initially assumed when I found a similar slime mould at Brandon Country Park back in winter 2024. In the post for that trip, I wrote:

In the field I assumed that they were Hemitrichia decipiens, but back at home, reviewing the photos, I wasn’t so sure. Do a search for Hemitrichia decipiens online and pretty much all the images are of a bright orange, globose or obpyriform fruiting body on a translucent white stalk. These sporangia, however, were mostly quite crowded with only a few with visible stalks and not so bright orange, more coral. I’m wondering if they might be Heterotrichia ferruginea.

I'm certain that this slime mould is the same slime mould that we saw earlier in the morning at the allotment — Heterotrichia ferruginea (likely).

Was the sporulating Heterotrichia ferruginea at the allotment and at Strumpshaw Fen — 15 kilometres apart — coincidence, or because the conditions were favourable across the region?

In the photo below, we see a group of peach-coloured sporangia (a little older) and plasmodium beginning to sporulate.

To the side of the root crown were some apricot-orange groups with many of the sporothecae in a state of collapse.

23rd December 2025

We visited the reserve again the next day and some of the groups were maturing to a honey yellow.

The sporothecae in the groups below still had a flesh-pink colour, but in the group at the top — and particularly the sporangia to the left — the sporothecae were collapsing.

The two groups to the side were drying out and some of the sporothecae were a shrunken, pale reddish brown.

28th December 2025

A week later, pretty much all the sporangia had dried out, turning to darker, matt shades of reddish brown, greyish brown and fuscous — some even black.

Some of the sporothecae were a pale beige with darkening tips.

Below — the plasmodium from earlier didn't sporulate and had changed colour with the sporangia. Could this be a sclerotium state — a dormant stage where the slime mould survives adverse conditions...?

1st January 2026

The small group below had a translucency about them, with colours ranging from yellowish and reddish browns to black.

Slime mould sporangia are quite small and it's not until you start to sift through the photos that you notice some wonderful details — like in the photo below, showing within one group a superb range of colours: from the captivating, dull yellowish-green sporothecae, to pale olivaceous-buff, pale clay-pink, fuscous and vinaceous-brown 🤩

25th January 2026

And a month on from when we first spotted the Heterotrichia ferruginea — the groups had faded to obscurity, but... two small new clusters of flesh-pink sporangia had appeared!