Fungus

You mean unconnected to bark necrosis or other outside symptoms of infection of the cambium ?

1. Tony did, by asking whether it turned yellow when bruised and smelled of aniseed, which are characteristics of the edible Agaricus arvensis, A. silvicola and A. essettii (= A. abruptibulbus). So what would have happened, if one would have eaten A. xanthoderma because the faint smell of rubber was mistaken for the (faint) smell of aniseed ? Last year a Dutchman, and the year before a Dutch woman died after eating field "champignons", that turned out to be whitish Amanita phalloides growing in meadows surrounded by oaks, from which roots the mycelium fruited. And in Sweden, every year people die because they mistake Amanita virosa for Cortinarius (= Rozites) caperatus. 2. Do you know how many people became seriously ill after they mixed up Laccaria amethystina with Mycena pura or Inocybe geophylla var. lilacea ? And what to think of mushroom guides listing the potentially deadly poisonous Paxillus involutus or "Russian Roulette Fungus" and Tricholoma equestre (rhabdomyolisis) as edible ?

Long before the tree was pruined, the infection with spores originally took place in a wound at the side of the tree with the bark necrosis and the mycelium didn't get far enough to the other side to reach the opposite pruining wound, because it beforehand retraced its steps via the radial rays to invade the cambium and cause the bark necrosis to develop at the side of the present fruiting.

Rob, Yes, such as Cordyceps militaris, a parasite living on pupae of butterflies.

David, Nice illustration of the fruiting mycelium taking the path of least resistance in bringing the FB out through the dead wood of the pruning wound below the bark necrosis and not waiting for the canker to "explode" and open up.

Two Psathyrella species, the bigger one at the base might be P. spadicea.

Bleeding red when scratched with a fingernail ? If so, Stereum rugosum. Not changing colour when bruised or scratched ? If so, S. hirsutum.

Sloth, I agree with Tony, the combination of ants feeding on it and the slightly sour smell are an indication of an Armillaria infection (rhizomorphs or plaques) of the cambium and the phloem and xylem. And the oak producing small, partially infertile acorns, is definitely panic fruiting.

Drew, Nice documentation of an endemic sundew species. And the fungus living on the bug probably is a Cordyceps species.

Another example of Fomitopsis pinicola on birch, I found today while monitoring a woodland on poor sandy soil with Betula, Quercus and Pinus as dominant tree species. ---

Correct .

Yesterday I found this example of final (partially) sterile panic fruiting of Meripilus giganteus from a living root of a last year felled beech, of which the stump had completely been grinded with only wood chips remaining from which Coprinus lagopus fruited to the right. ---

I expect your last suggestion to happen, but nothing as unpredictable as the future fruiting of an annual macrofungus .

Sporocarp is the name used for the reproductive phase of macrofungi, i.e. for FB's (anamorphs and teleomorphs) in general.

No, I can't answer that question. I don't think, however, that they are fungal based.

Paul, The combination of turning yellow when cut or rubbed and the smell of hospital disinfectants (phenol) is species specific for Agaricus xanthoderma, a poisonous champignon !!! And I only answer your ID-call to warn anyone picking field mushrooms never to eat fungi "identified" by photo (and description) through the internet !!!

Tony, I assume, you mean the anamorph producing chlamydospores.

This type of small bulbous growth sometimes develops into a bark canker caused by Nectria ditissima.

Sean, Judging by the FB's following their "tracks backwards" on the major roots towards the root tips, I assumed, that at least the roots still had living tissue, that was invaded by the mycelium.

David, : G. pfeifferi ?

Nick, 1/2. Polyporus varius. 9. Knopper gall (Andricus quercuscalisis).

Yes, this is an example of panic fruiting of the mycelium of Meripilus giganteus from a beech stump, that still has living tissues to support the decomposition of dead wood to produce FB's from by the mycelium, that has infected the tree in the background too through root-root contact and also fruits from this tree, because the mycelium "as a whole" is triggered to (panic) fruit simultaneously.

Tony, Yes and no. I would rather consider this to be first time prolific fruiting of a necrotrophic parasitic Armillaria with intensification of the killing of the remaining living tissues of the tree, triggered by cutting the tree at its base, because the Honey Fungus will still have the opportunity to further decompose dead wood after the tree has died completely.

In this respect we totally agree .