Dichostereum rhodosporum

This is a corticioid fungus, hence with a fruit body that is a sheet-like growth on dead wood. There may be scattered ‘warts but, in essence, the fruit  body is smooth. Fruit bodies start as small patches and, as they expand separate patches may merge to yield a single, continuous sheet of irregular shape that covers many square centimetres. The colour may be creamy, buff/ochraceous or very pale brown and a well-developed fruit body is a thickish crust (with a consistency somewhat like hard rubber) that is attached tightly to the wood. The margin is fairly well-defined but there may very short, wispy fringes in parts.  

Look-alikes

Microscopic features differentiate this species from others in the genus. Some species of Vararia or Scytinostroma have such rubbery-crusty fruit bodies of similar colour and Dichosterum rhodosporum was once known as Vararia rhodospora.   

If you see a flat, creamy to pale brown, smooth, firm-rubbery, well-attached fruit body then it’s likely you have a fungus in this group of three genera.

The same colours are found in many corticioid fungi but you can usually rule out the Vararia group if the fruit body has one or more of the following features: not smooth (e.g. well-covered with warts, teeth, ridges, etc); soft; very thin; loosely-attached; with numerous cracks, especially if they are more or less parallel or if the fruit body is areolate or polygonally cracked (like ‘crazy paving’); broad, diffuse margin (perhaps with numerous thin, thread-like outgrowths); along the margin there is a narrow band of a colour markedly different to that of the rest of the fruit body.