These were found in the forest around my university. This is a myxomycete (plasmodial slime mould) forming fruiting bodies as the conditions are becoming too dry for its liking. These lovely creatures start out from spores either as flagellate or aflagellate amoebae. The environment determines which set of genes is turned on in order to 'build' the flagellate or aflagellate form! The amoeboid stage is where sexual reproduction happens. Later, the amoebae aggregate in groups and do something amazing -- fuse themseleves into a gigantic multinucleate plasmodium! This plasmodium moves around eating bacteria, with the thicker leading edge pointing to where the abundant food is.
Later, as the conditions become unfavourable (exhausted food supply and/or drought), they organise themselves to form a fruiting body, which then releases spores further away, towards a new food source.
These photos were taken by my friend while were were slime mould hunting. The first one shows a plasmodium forming fruiting bodies, the second image is likely the same species but at a later stage. The brown powdery 'stuff' is the spores. The last photo seems like a different species, although I'm no expert in this field. If anyone could help out, that would be really nice! Oh, and the very last photo is Sparassis crispa, which is apparently edible.
(Photos by Achiru, 2008; EDIT: NB - last image is a fungus, not slime mould)
The Green Sulphur Bacteria
1 hour ago in Catalogue of Organisms