Big, Blobby Slime Mould

 

 Walking back from the polling station on the day of the general election - 4th July - I came across this large, pale slime mould newly emerging from a mossy, recumbent beech trunk. From the size and colour I assumed it was Brefeldia maxima. 

 

Over the next couple of weeks, I returned to the site to watch the spore mass develop. Through the first 48 hours, it turned a deep black-currant red.

...and then dried out and turned chocolate brown.

Brefeldia maxima has a well-formed, continuous skin covering the spore mass (called the cortex) and this slime mould did not, and on examining the spores with a microscope more discrepancies appeared: 

The retuculate spores and net-like capillitium suggest this could be Symphtocarpus amaurochaetoides. My main reservation about that id is that the spore mass was so much larger than it should be - about 40x12cm where the description (in 'The Myxomycetes of Britain and Ireland" by Bruce Ing) suggested 5cm diameter was usual.

You can monitor or contribute to this observation on iNaturalist, here.

 

 

On my last visit to check on the slime mould, a large sphere of spore mass had fallen off the log and landed on the forest floor. A dor beetle had found it, and seemed happily engrossed in rolling it around the leaf litter.

I just caught the tail end of the performance on video: dor beetle exit stage down to the consternation of the mites.