I think this is perhaps developing Exidia nigricans ( = Exidia plana) known as Warlock's Butter. However I'll have to go back to collect some to see if I can really tell it apart from Exidia glandulosa (=Exidia truncata), also known as Witches' Butter. Mixed woodland near Tonbridge.

The calm before the storm.

 

Walked slowly through Fox Wood, then finally around the short loop. Plenty of Stereum hirsutum, one log with Stereum subtomentosum that I had seen before, lots of Schizopora paradoxa, then with a possible Phlebia rufa, something unknown on a spruce, the yellow jelly parasite, then the suspected Stereum gausapatum on the fallen oak branch - of which I am no longer so sure, it hardly has any margin at all.

The Oak Curtain Crust, Hymenochaete rubiginosa, probably

Hymenochaete rubiginosa, (Dicks.) Lév.

This crust is smaller than I thought, at least the small cap structures of this specimen! I rather think this is a fairly old specimen, as it seems very dark on the underside, the hymenial surface. The pin is about 10 mm across.

The resupinate form may perhaps be seen to the left of the caps?

Kibby states that the fruitbody is partly sessile to bracket-like and this caps are I think intermediate between these extremes. He also has them often fused in rows, which these are not, but I would say that the upper surface is "characteristically undulating". The caps are very dark, Kibby having them as red-brown to blackish, with reddish or ochre (?) marginal zones.

When young the hymenial surface could be a much brighter colour, perhaps reddish ochre to rust red, but if I am correct, by now it is a very dark brown. 

It would definitely be worth looking with a hand-lens for the projecting hymenial setae on this species, as they should be made more conspicuous because of their dark brown colour.   

Fuscoporia is as close as I can get!

 

In Dene Park I have found quite a bit of Fuscoporia on over-stood dead Sweet Chestnut trunks, which makes it one of the commoner crust fruiting bodies in this woodland. This might raise the question why it isn't mentioned as a host in H & L - except maybe there aren't many Sweet Chestnuts in Hampshire, especially ?

A closer pair of views of the above, maybe suggesting a largely eroded fruiting body, perhaps not the best for microscopy...

In First Nature, only Fuscoporia ferrea is mentioned, and it is said to be common and widespread in the UK as well as Europe. I think there is a general agreement that Fuscoporia ferrea is the more commonly recorded taxon in the UK. Distinguishing the two is likely to be very difficult and some would say based on microscopy alone.  It may be worth checking that the tubes are brown, 2 to 5mm deep in each of 4 to 5 layers, as the tubes seem to be much deeper than that in some of the specimens I have seen; they should also terminate in small roundish red-brown pores spaced 4 to 6 per mm. Kibby on the other hand has the tubes up to 8 mm deep, and concolorous with the pores. What is a beginner supposed to do?

I always find it amazing that despite the bright colours of the fruiting bodies and layers, that the spore print is only white or whitish - it must be difficult to determine of course, as large numbers of spores are required for a print.

Fuscoporia ferrea is mentioned as the cause of a disease of stone fruits in the NBN, but I have found no cross-referenced support.  There is the rather similar Phellinus pomaceus. 

Distinguishing ferrea from ferruginosa is definitely tricky. In Laessoe and Petersen it suggests that only ferruginosa has setae in the margin. Kibby appears to suggests they are also much larger than the hymenial setae - 300 micrometers - but this is really not implied in Laessoe and Petersen!

On another nearby Sweet Chestnut trunk of over-stood coppice, we may have an example of the false caps mentioned in L & P. Another explanation might be cavities stuffed with brown hyphae -very difficult to interpret! 

 

Hairy-felty poroid bracket

 

Brown topped but this dried to a very dull grey-brown because of the very densely felty-hairy surface. The edge was blunt rather than sharp and the under surface was white going to cream with 2 - 5 pores per mm.

The bracket was umbonate with a narrow point of attachment. I wondered whether it was a Trametes species because of the hairiness of the cap.

Stereum gausapatum probably

 

Walking in Fox Wood this muddy and very slippy afternoon, and trying to give Toby as much ball-chasing as possible, just as we came to the start of the upgrade and the spruce plantation near the road, there was a large oak branch down on the ground, about 20 cm diameter and a good 8 m long or more. One large fruiting body of what was most likely to be the Bleeding Oak Crust Stereum gausapatum (Fr.) Fr. was very obvious in its chestnut colour. It reddened consistently when rubbed - top right of the crust in the third image. 

Fuscoporia it seems

 

A large spread of this vivid brown crust fruiting body on this fallen branch. It is assumed to be either Fuscoporia ferrea (Pers.) G. Cunn. or Fuscoporia ferruginosa (Schrad.) Murrill. and I think you cannot tell the difference without microscopy.