What are known as the “plasmodial slime moulds” are amazing. They germinate from a spore as a single cell amoeboid  cell that is grazes freely on bacteria and detritus in the free water between soil particles and in decomposing wood. When two compatible amoeboids meet they fuse and form a multi-cellular plasmodium which can reaches a size that is visible to the human eye. The plasmodium continue to flow through the soil and decaying wood engulfing bacteria and other microorganisms. This was the basis of horror movies like The Blob. Have a look at the Deep Look YouTube clip for time lapse photography of plamodial movement- you may enjoy it more with the sound off 🙂.

When conditions are right, and the plasmodium is well fed it will go through a metamorphoses  and be transformed into a fungal like fruit body. It was for this reason slime moulds have been studied by mycologists and appear in mycological textbooks. The following photos of Stemonitis fusca, were taken by Barbara Appleton and identified by David Appleton in their garden in Palmerston North. This slime mould was living in a tree stump of Atlantic cedar (Cedrus atlantica) which had been left to rot. These photos show the metamorphoses of the plasmodium as it coalesces into a round flattened blob which quickly becomes nobbly.

By the time the spores are mature the entire fruit body has dried out and the outer sausage skin is disintegrating leaving the stalk with its open scaffolding of tubules containing the spores which are now free to drop out and be blown about in the wind. Those spores that land in suitable habitats will germinate to release a new amoeboid cell.

If you are wanting to read more broadly about slime moulds a good article is: Penny Cullington’s “Slime moulds for beginners” (Field Mycologist 10(3): 77-85, 2009).

If you are wanting to identify New Zealand slime mould you need Steve Stephenson’s “Myxomycetes of New Zealand” (Volume 3 of The Fungi of New Zealand / Nga Harore o Aotearoa).