

It's growing on a decaying tree trunk and stump (probably horse chestnut) in Pishiobury Park just north of Harlow on the Essex/Herts border, and behind Victoria Beckham's garden. The fungus emerges looking like a quail's egg, from this comes what looks like a white furry goose-egg. This opens out to the size of a large teacup or small pudding basin with a furry stalk.
We've looked through three fairly detailed mushroom and fungi identification books and also looked at the web site Rogers Mushrooms, so far without success. Surely such a dramatic and distinctive fungi should be easy to identify. Does anyone know?