Fungus and Fairies

The other day while we were tramping about near the creek, we came upon a colony of cantaloupe-sized giant puffballs growing in the grass. They were past eating, but reminded us of an episode a few years ago while we were living in a big apartment building. One autumn day, Bryan found a puffball as big as a soccer ball growing in a field. He brought it home. Through careful research, we found that if the puffball was pure white on the inside, and had no gills, it was edible. If it had gills it was poisonous. We didn’t find any gills so it was safe to eat. We cut it up and fried it and ate it. It wasn’t wonderful, but it wasn’t bad. We threw the leftover bits in the trash and congratulated ourselves on being good foragers.

A few days later Bryan commented on the handsome metallic green flies on the kitchen window. I was aghast—blow flies! They come from maggots, and maggots come from flies laying their eggs in dead things. Yikes—our neighbors must be terrible housekeepers! We emptied the trash and got rid of the flies, and a few weeks later, to my chagrin, some further reading about puffballs revealed the source of those flies. They had come in as little white maggots in the white flesh of the puffball mushroom, impossible to see. Too late to worry about eating them!

On this fall day in Iowa, nine of these puffballs were scattered around in the leaf litter. They were well past their prime and had probably already sent their billions of spores sailing on the wind.

Giant puffballs are found all over the world. They grow in Europe and Asia as well as in North America. They are common east of the Great Plains, including the vicinity of Owl Acres. They grow in fields and lawns, at the edges of forests, and on a variety of prairie soils.

Giant puffballs are actually the above-ground part of an underground fungus (Calvatia gigantea). This fungus is not a parasite like many fungi. Instead, it is saprobic—that is it feeds on dead things. You may wonder how a fungus can actually feed on anything. Here’s how it works. The underground part of the fungus is called the mycelium. It is made up of a network of hundreds to thousands of thin tubes. At the tips of these tubes are structures that release digestive enzymes onto dead grass, animal matter, leaf litter, dead wood and similar environmental detritus. These enzymes digest and liquify the “food” and then the fungus can absorb it to feed itself. In this way, the fungus helps recycle decaying plant and animal matter into nutrients.

The puffballs we see are the fruiting bodies of the underground fungus. They usually occur in late summer and fall. They grow very quickly to form a ball up to 20 inches in diameter. They are pure white as they grow, but turn brownish as they age and mature. The inside is also pure white, and the flesh has the consistency of—well—a mushroom.

The job of the puffball itself is to create and release spores—trillions of them—from within the body of the mushroom. Have you ever stomped on one just to see that green-brown cloud of spores erupt? With that many spores, you’d think there’d be lots more puffballs, but they’re picky about where they land.

The puffballs we found were scattered about, but sometimes puffballs are found in a circle, known as a fairy ring. The fairy rings are created as the underground mycelium spreads out from the center, looking for more dead things to ingest. The mushrooms pop up at the perimeter, forming a ring. Left undisturbed, they may come back year after year in ever larger rings as the underground fungus continues to grow.

These fairy rings have mythologies in a variety of cultures. The Blackfeet Indians who traveled the Midwest prairies believed that the puffballs were stars that had fallen from heaven. The people of the British Isles thought they were places where fairies, elves or pixies danced and played. Some cultures thought they were enchanted spaces—others that they were associated with witches or the devil and should be avoided.

Native Americans found many uses for puffballs. They collected them and created a powder that was used to stop bleeding or to protect open sores from infection. The powder was also used to treat earache, chafing, and the umbilical cords of newborn infants. Compresses made from the spores and spiderwebs, and held in place with strips of birch bark were also used for wounds and swellings. Research has found that the spores are actually antibacterial, antifungal and antimicrobial which would explain their effectiveness in treating wounds. Indians and settlers alike harvested young puffballs for medicine and for food.

We didn’t harvest the giant puffballs we found this year. They were too old. However, we’ll be on the lookout late next summer and fall for fresh ones. They don’t taste all that great, but foraging for food in the woods and fields has its own attraction.

Photo by Author