Slime Moulds in Windthrown Root Hollow
RSPB Strumpshaw Fen Woodland – October 2024

27 October 2024

In early October in the same windthrown root hollow where we found Stemonitopsis typhina we saw gregarious groups of what may have been a Trichia species. In the photo below, on the right, there are white juvenile sporangia and on the left maturing honey-yellow sporangia.

Slime moulds in windthrown root hollow
Strumpshaw Fen woodland – 6th October 2024

White sporangia on the right.

White juvenile sporangia
Strumpshaw Fen woodland – 6th October 2024

Honey-yellow sporangia on the left.

Maturing honey-yellow sporangia
Strumpshaw Fen woodland – 6th October 2024

The white juvenile sporangia are amongst what are likely to be old Stemonitopsis typhina — as can be seen in the close up below

White juvenile sporangia and likely old Stemonitopsis typhina
Strumpshaw Fen woodland – 6th October 2024

The maturing honey-yellow sporangia are developing over what looks like creamy white plasmodium. But is this the plasmodium of the honey-yellow sporangia or is it a plasmodium from a different species?

Maturing honey-yellow sporangia and plasmodium
Strumpshaw Fen woodland – 6th October 2024

To the left of these maturing honey-yellow sporangia are more probable Stemonitopsis typhina. To the lower right of the main bunch of S. typhina is a cream layer of what looks mouldy slime mould sporangia some of which appear to be parasitised by a Stilbella fungus. Note the six pale yellow sporangia lower centre.

Likely Stemonitopsis typhina, mouldy sporangia and six pale yellow sporangia
Strumpshaw Fen woodland – 6th October 2024

A couple of weeks later, the white juvenile sporangia on the right had matured, while the maturing honey-yellow sporangia and plasmodium on the left had undergone a fascinating transformation.

Slime moulds in windthrown root hollow
Strumpshaw Fen woodland – 20th October 2024

Adjacent the right group three new groups of curry-yellow sporangia had formed.

Honey-yellow and curry-yellow sporangia groups
Strumpshaw Fen woodland – 20th October 2024

Close up of the adjacent curry-yellow sporangia.

Curry-yellow sporangia
Strumpshaw Fen woodland – 20th October 2024

In the fascinating left group most of the sporangia from a couple of weeks ago had become parasitised by Stilbella, with a smattering of darker mature sporangia also present. However, there were also numerous younger sporangia — white, curry-yellow and honey-yellow, likely originating from the plasmodium that we observed a couple of weeks earlier.

Collection of sporangia at various lifecycle stages
Strumpshaw Fen woodland – 20th October 2024