Hapalopilus nitidans, the Cinnamon Bracket or Tender Nesting Polypore.

The UK's only toxic polypore - and it is HIGHLY toxic with a very high content of polyporic acid.

While with the Kent Field club group, we found a very lovely looking triangular bracket fungus on a small dying or dead tree. I would describe the form as "stepped". I tentatively identified the host as a Rowan or Sorbus tree and somebody who I think must have seen this bracket fungus before, tried putting some potassium hydroxide, KOH, on it. It almost immediately turned a bright violet colour suggesting that it was the toxic cinnamon bracket. Hapalopilus nidulans, a very difficult name to spell. I was pleased to say that Lassoe and Peterson also consider it quite commonly found on Sorbus. However, other sources just give it as found on mixed deciduous trees or possibly Oak and Birch. It was a delightful colour and an interesting texture on the top surface. All the factors seem to fit, so a nice step forward in bracket identification for me.

Also referred to as Hapalopilus rutilans, it might be rather commoner in Europe, but is said to be only occasional in the UK. Records in the UK seem to fairly evenly distributed north to south. This is an annual polypore bracket, breaking down to a rather dusty debris. However, these 2 or 3 brackets were quite fresh.

Note the texture of the top surface, sometimes likened to suede. The top is said to be flat to slightly convex, the overall texture of the bracket soft.

Said to be typically "triangular" in shape.

The pores are quite coarse and strongly delimited in appearance. 2 - 3 per mm. Tubes reportedly up to 1 cm deep, spore print white. There is a fairly clear margin to the underside, extended rollover in the later stages.