A naturally occurring circle or arc of mushrooms. The process of formation is thought to relate to the availability of nitrogen to the underground part of the mushrooms, the mycelium. This mycelium spreads outwards from the centre until it has used up the nitrogen in that bit of the soil at which point the central portion dies back and the living portion at the edge fruits to reproduce and establish new colonies. Sometimes the presence of the mycelium is visible by a ring or arc of dark grass even when fruiting does not occur. Superstitions and myths surround these features, often identifying the rings as places of enchantment, both malevolent and benign.
Etymology
Dialect, related to the many superstitions and legends associated with the phenomenon.