I have been up in the woods today and yesterday (3rd and 4th June) rather belatedly starting to cut and collect timber for this winters fire wood store. I noticed several bright yellow slime moulds on some of the old Corsican Pine stumps.
Today I could only find two, one was quite bright and looking fine, the other had a brown edge to it. I collected about 6 barrow loads of wood, which we had cut up yesterday, then spent some time spraying some of the brambles which were encroaching on my paths and then eventually took some photos of the slime moulds.
Slime moulds are weird. They start life as single cells rather like amoeba. These unicellular amoebae feed on bacteria and other microorganisms. These amoebae can mate if they encounter the correct mating type and form a diploid cell or zygote which can then grow into what is known as a plasmodia. These contain many nuclei and can grow to be meters in size. The species in the photos is Fuligo septica and is often seen as a slimy yellow network in and on rotting logs. The amoebae and the plasmodia engulf microorganisms. The plasmodium grows into an interconnected network of protoplasmic strands.
When the food supply wanes, the plasmodium will migrate to the surface of its substrate and transform into rigid fruiting bodies. The fruiting bodies or sporangia are what we commonly see; they superficially look like fungi or molds but are not related to the true fungi. These sporangia will then release spores which hatch into amoebae to begin the life cycle again.
So despite their name Slime moulds are really quite interesting and have characteristics which are both animal and plant.