Pyronema sp. (A fire fungus)

The fruit body (an apothecium) is a small, circular cushion, up to about a millimetre in diameter and pinkish, light red or reddish-orange. The apothecia are smooth. Typically they appear in large numbers, so tightly packed that mutual pressure distorts the circular shape. Moreover, from even a relatively short distance the dense packing means that it may be impossible to distinguish individual apothecia so all you see is a coloured wash over the substrate. A closer look, especially at the margins, may reveal individual apothecia.

The apothecia are likely to be seated on a network of hyphae which, from a short distance, looks like a white filmy or cobwebby layer over the substrate. Again, this may be easier to see at the margin of the massed apothecia.   

The fruit bodies are seen most often on recently burnt ground but are found also on new plaster. They occur in a wide variety of natural habitats.    

Look-alikes

There are other reddish to orange apothecial fungi that occur on burnt ground (e.g. species of Anthracobia). However, their apothecia are larger (from 1 to several millimetres in diameter) and, even when clustered, the individual apothecia are much easier to distinguish. Apothecia of the other genera are also likely to have marginal hairs (albeit possibly short and stubble-like) and lack the extensive white, hyphal network.