Fairy rings are magical places, nearly perfect circles of mushrooms that run from a few to many feet in diameter. Also called fairy circles or pixie rings, they were more often seen in the days when pastures were common and before chemicals and frequent mowing turned lawns into monotonous carpets of green.
A fairy ring marks the edge of an underground growth of fungus, called mycelium. This subterranean body spreads slowly outward, emitting chemicals ahead of it that convert organic matter to food usable by the fungus. When the time is right, the mycelium shoots up mushrooms at its outer edge. Like flowers on plants, they distribute spores that will create future fungi and, perhaps, fairy rings.