Saturday, October 9, 2010

Slippery and Slimey

The current spell of mild wet weather has provided perfect conditions for this fine specimen of Suillus bovinus, a close relative of slippery Jack S. luteus, that we found around the roots of some Scots pines beside the South Tynedale Railway at Alston this morning.

The whole surface of the cap in this species is covered in a slippery mucilage. As the toadstool ages it gradually turns darker brown, but this specimen is the prime of life. The books say it's edible but I'm not tempted.....


Suillus is a polypore, releasing its spores down the narrow tubes that line the underside of the cap.
Slippery Jack is indeed slippery, but not in the same league as the organism that was creeping through the grass on the other side of the footpath.

This is the slime mould called Mucilago crustacea. Slime moulds, or myxomycetes, are amazing organisms and if they didn't exist science fiction writers would surely have to invent them. They begin life as individual microscopic amoebae that hatch from powdery spores that are released from the wrinkled surface you can see here. The amoebae aggregate and fuse together to form a creeping, translucent plasmodium, that moves across the surface of wet soil, grass, wood and rocks digesting bacteria and dead material that lies in its path.

If you look closely at the image above you can see the plasmodium - the translucent part, with thickenings that look like veins - stuck to the dead grass in the foreground and hanging in a blob slightly above and to the left.

This plasmodium is almost fully fed and its wandering days are over. The leading edge, seen here is already wrinkling, is beginning to produce vast numbers of spores on the surface of those convolutions and these will dry and blow away in the wind or be washed away by rain..... to germinate again and release swarms of amoebae

 You can find some very fine movies of the creeping plasmodial stage here and here


  1. Very interesting, seems to know much about mushrooms .., to tempt me to eat them:) .. good capture, i like it..

  2. Once again thank you for all this. I never knew they existed but will keep my eye out for them now fascinating aren't they.

  3. I'm with Adrian on this; never heard of them before Phil. Fascinating. They really are like something from a science fiction film.

  4. I remember being taught a little about the amoebae at school but had no idea they could work together like that - very scifi-ish and fascinating.

    Thinking of slime I have been watching some fungi growing on an old tree stump which over 7 to 10 days has degenerated into a mass of black slime.

  5. Hi Dejemenos sorprender .... I don't know enough to risk eating them...

  6. Hi Adrian, I find fungi more interesting than plants or animals (but I may be weird)

  7. Hi Keith, I've germinated the spores and they really are like roving, microscopic amoebae...

  8. Hi John, it seems to be the season for slime moulds around here lately.... I saw a lot of them in the Tyne valley yesterday..