At the base of the medlar trunk I found a, small, hard bracket fungus. With the help of Martin Allison, the county fungus recorder, this was determined as Ganoderma applanatum, the artist's bracket or artist's conk.
A distinguishing feature is the soft, thin, whitish surface underneath which if scratched leaves a brown mark. This surface can be used for writing or drawing as with white scraperboard (or scratchboard). The example below is on the under side of the fungus above. It looks strangely like a graffito written over a cave painting.
Some artists have produced remarkable effects. Have a look at these drawings by Marie Heerkens which are somewhat better than my script:
Recent research has shown that chemicals from this fungus could be of value in the treatment of diabetic complications. It is also said to make an excellent, if rather bitter, medicinal tea. However, what it was excellent for (or against) was not specified. It can also be used for dyeing wool, some fabrics, or paper and will yield a rust colour with wool when ammonia is used as a mordant.
Ganoderma applanatum causes white rot within the host tree, which explains why a large chunk of the medlar died back last year. I expect the rest will go fairly quickly, but some suckers may survive. It is rather sad really as it is a wild medlar (with thorns) that came, many years ago, from the bank close to my parents house at top of Whydown Hill at the far south of the parish. Ganoderma, mankind or medlar, we are all headed for the same destination.