Amanita muscaria, Fly Agaric.
The mushroom beloved by fairy-tale books and pixies, if children are still allowed these. The bright red cap with white patches (which are remnants of the covering veil) can reach almost 30cm in diameter, although it is usually smaller in Guernsey. The gills are white, as is the stipe with its large hanging ring. The base of the stipe is bulbous, with horizontal ridges. This fungus is a woodland species, usually associated with Silver Birches, but in Guernsey it is often under Pines, possibly because we have more of these than Birches. It is not very common, although some years, such as 1991, it can be prolific. The chemicals within it are hallucinogenic and can cause very unpleasant effects, although it is not usually deadly unlike its close relative the Deathcap. If crumbled in a saucer of milk, it is said to kill flies.