File:A slime mould - Metatrichia floriformis - geograph.org.uk - 1493934.jpg

English: A slime mould - Metatrichia floriformis [For details of the habitat, and of the climatic conditions which caused an abundance of slime mould species in this area, see 1493931, which shows a different species growing alongside this one on the same log. See 1528103 for a list of all five species found on the log.]

These shiny little black spheres are just under a millimetre in width, and are the spore-producing bodies of the slime mould species Metatrichia floriformis. The shiny outer layer (the peridium) splits open in a way that suggests the petals of flower (hence the "floriformis", "flower-shaped"), although in a slightly more ragged fashion. The fluffy yellow mass inside consists of threads called elaters; see the link in the first paragraph for a description of their function.

(A few days earlier, before the black spheres had formed, the slime mould appeared only as a dark reddish-brown smear on the wood, rather like a patch of oil.)