Fuligo intermedia  T. Macbr.

Fuligo intermedia  T. Macbr.

Monday, 10 April 2017

A spongy mass of plasmodilum on beech leaf litter was collected in Lady Park Wood, Forest of Dean on 7th April 2017. The plasmodium was cream coloured, and darkened over the following 24 hours as it developed into a heaped pseudoaethalial mass of sporangia.

Lime nodes small, sparse, irregular, physaroid, capillitial threads not detected.

Spores 11 - 14µm Ø dark brown in mass, and by transmitted light, minutely verruculose, almost smooth and evenly coloured pale brown under oil (x900). 

x 200

x 500 

x 900 oil

Initial diagnosis:  Physarum cf confertum, but peridium is chalky grey, not dark blue-grey.

Differs from  Physarum gyrosum (aka  Fuligo gyrosa ) in:


- larger spores


- lime nodes not extending from wall to wall


- hypothallus white


- no dark clusters of spinules visible on spores


Compare also with  Physarum compressum.


Unlike typical Fuligo intermedia, no cortex was present, perhaps as a consequence of collection whilst still immature.

Individual myxocarps were approx 0.5mm in diameter, initially dark grey, drying light chalky grey, patterned with white lime and sprinkled with shining circular dots, an artefact of collection/drying).