Fungus

David, I overlooked your question. Quercus rubra was introduced to The Netherlands in 1825.

Andrew, 1. See 2. Biotrophic versus necrotrophic parasites. 2. Sure, but where does (most of) the water content (and its defensive "ingredients") within the tree come from ?

Tony, Never seen this and the only parasites on FB's of C. fusipes I know are Nyctalis (= Asterophora) lycoperdoides and N. parasitica. And do you know this research on the effects of C. fusipes on Quercus robur and Q. rubra ?

: Phytophthora leaf & twig blight caused by the oömycete P. ilicis.

Rob, A Peziza species, such as P. vesiculosa, P. repanda s.l. (incl. P. micropus) or P. cerea s.l. (including P. varia).

Glen, 1. Probably a bolete, with red pores ? If so, Boletus erythropus or B. luridus. 2. , probably G. australe. 3. Maybe a very young "bud" or primordium of the Ganoderma species.

Yesterday, I found Hydnellum spongiosipes, one of the Hydnaceae associated with Quercus robur or Q. rubra and sometimes with Fagus, Castanea or Betula on poor sandy soils, a species that has become rare because of nitrification. The close up (20 x) of the spines - with sand grains op top - was made with my digital microscope. ---

Apart from Serpula lacrymans, which is not a "field" species, I suppose it could f.i. be expected from some dry brown rot causing species, such as Laetiporus sulphureus, when the mycelium (mycelial felts) is only present in the heartwood of f.i. Quercus robur without being connected to moisture holding living tissue through the radial rays.

So is Pleurotus ostreatus, but the white rotters of branches still present in the crown or fallen on the ground are restricted to common saprotrophic generalists such as Vuilleminia comedens and/or Stereum or Tremella species and to one tree species specific Peniophora species, P. rufomarginata. On the dead epicormic growth at the trunk's base, one can find Mycena species and I twice found Entoloma conferendum var. pusillum (= E. xylophilum) fruiting from these dead twigs.

Matt, Psathyrella species, could be P. prona s.l.

Pete, 1. Only significant for a mycologist, who wants to identify and document a species with 100 % certainty . 2. I think, it's restricted to saprotrophic (dry) brown rot causing species degrading (processed) wood inside buildings, that have to decompose wood under relatively dry circumstances.

The top three of pathogen macrofungi most invasive and detrimental to the trunk's base and major roots of Tilia spp. are Kretzschmaria deusta (soft rot), Meripilus giganteus (white and soft rot) and Ganoderma australe or G. lipsiense (white rot with selective delignification).

Until now, in The Netherlands I've documented P. fraxinea on Platanus spp. three times. All trees were heavily reduced before, leaving the major roots and the endomycorrhizal microfungi associated with them no longer supplied with energy/sugars behind, which caused the no longer adequately protected and "nurtured" major roots to partially die without Platanus as a species being able to regenerate major roots insufficiently supported by a for the greater part defoliated crown. The mycelium first "empties" the sugar/starch rich radial rays before it starts decomposing the central wood column of the tree base at or below ground level. Other (biotrophic) parasites attacking Platanus under these circumstances are Meripilus giganteus, after loosing its major roots triggering the tree to form a dense secondary root system of adventitious roots around the trunks base to supply the remaining crown with water and nutrients and Pholiota squarrosa, mainly undermining the buttresses, major roots and trunk's base beneath ground level and destabilizing the tree.

No, microscopically checked Guignardia aesculi, what else would you expect of a mycologist ?

Pete, 1. Did the "FB", that looks like an anamorph "panic" fruiting, contain basidiospores or chlamydospores ? 2. From the rhizomorphs of the dry brown rot causing Serpula lacrymans is documented, that they transport water, that stays behind in/on the wood (lignin) after the cellulose is decomposed and "consumed" in one place, is transported to "dry" places to "moisterize" the wood elswhere before the mycelium starts to decompose the cellulose there. And it is also documented, that hyphae and/or rhizomorphs of S. lacrymans can detect (pieces of) wood on the other side of a brick wall and grow/stretch in a straight line towards it by penetrating the wall through the seams.

Pete, Great documentation with the yellowish brown (guttation ?) droplets on the mycelium. It could also be (the mycelium of) Antrodia serialis, which is more often documented from processed coniferous wood.

Cortinarius species, probably from the Subgenus Leprocybe or Dermocybe. Identification : microscope and Breitenbach & Kränzlin, Pilze der Schweiz, Band 5, Blätterpilze. Cortinariaceae.

With a membranous ring or with a woolly-fibrillose veil or zones ? And if associated with trees, what species (Betula) ?

Matt, 1/3. On coniferous wood and with grey gills ? If so, Hypholoma capnoides. 4/9. With pores and thin perennial tube layers ? If so, either Phellinus ferreus or P. ferruginosus. 10/14 . Armillaria mellea.

1. With tubes/pores or gills and with what colour of pores or gills and spores ? 3. Oakleaf mildew (Microsphaera alphitoides). 4. Pinus spp. ? If so, it can be Gremmeniella abietina, a Lophodermium species or Sphaeropsis sapinea.

Tony, I fear the same fate for your chestnut, because as long as the dead wood wound is not closed, it is the perfect place for (necrotrophic) parasites such as Pleurotus ostreatus or Armillaria, Polyporus and Nectria species and/or saprotrophic species, such as Trametes versicolor and Bjerkandera adusta, to find a foothold.

David, Great documentation of the phenomenon of panic fruiting .

Rob, As S. torminalis is not an endemic species in The Netherlands, we only have a few smaller trees planted in parks. But we do have lots of Sorbus terminalis .

... and diminish the competition for endomycorrhizal symbionts with grass and other plants, on which' mycelia the tree and plants both highly depend for the uptake of water and nutrients from the soil food web and for the protection of their roots against parasites.

Inonotus dryadeus on maple ?