If we get plenty of rain in the next few weeks we should see an explosion of fungi. What we see is only the fruiting body of the fungus, a bit like an apple on a tree. The rest lives unseen beneath the surface, possibly for many years.
The most familiar is the Fly Agaric, Amanita muscaria: bright scarlet with white warts, often found near birch trees. It's quite common in our district and it's one of the most beautiful of all mushrooms, but it is highly toxic and must never be eaten. As a rule, never eat any mushroom with white spores.
It has featured in folklore for thousands of years, from Siberian rituals to Alice in Wonderland. As G.K. Chesterton put it, the world will never starve for want of wonders, only for want of wonder.