Clusters of mushrooms popping up after lots of rain isn’t a surprise, but some
Arkansans are currently seeing a particularly charming fungal array commonly known as fairy rings.
Lance Blythe, Greene County extension staff chair for the University of Arkansas Division of Agriculture, has noticed lots of these formations lately. Rounds of heavy rain have made conditions perfect for fungi to thrive.
Not all of these rings are circular. Blythe found one that was a small circle embedded on
the edge of a half circle. Another even looked like the outline of a dog’s head from a
certain angle.
“There is a legend that fairy rings are formed in areas where fairies dance. However,
there is a more scientific explanation,” said Vic Ford, a fungus expert who is also
associate director for agriculture and natural resources for the Cooperative Extension
Service.
“Fairy rings are formed from the growing of the mycelium of mushrooms in grass,” he
said. “The mycelium is the vegetative part of the mushroom and causes grass clippings
and debris to decay.
“During the decay process, plant mineral nutrients are released that fertilize the grass,
creating the darker green appearance,” he said. “Also, plant growth hormones stimulate
the grass growth. The fairy rings associated with grass in lawns, meadows, and golf
courses are called free fairy rings. They form when a single spore gets established in
the grass and begins to grow.”
As decayable material for the mycelium is depleted in the center, the ring expands
further away from the center” enlarging the ring, Ford said.
“These rings can be centuries old, with a fairy ring in France being documented over
700 years old,” he said.
The most common free fairy ring in Arkansas is formed by the fungus, Chlorophyllum
molybdites. Commonly known as the false parasol mushroom, it has green spores and
is known as a “vomiter.”
“It is definitely toxic to people and pets,” Ford said. “Tethered fairy rings” are associated with trees, he said. These occur when mushroom
mycelia are growing symbiotically with the tree roots. As the tree roots expand, the
mycelia follow the expanding roots.
Ford said, “Enjoy the beauty of fairy rings but watch for the ‘fae’ folk!”
