Mushroom hunters can't stop finding mysterious fungi

Strange things appear in the forests and chaparrals of California after heavy rains. Moist fungi that live quietly in the soil create fruiting bodies. Some have the familiar mushroom shape of a stem and cap, but others resemble fluorescent coral, wads of translucent brown jelly, and bright yellow buttons — strange shapes visible to the naked eye only briefly while the organisms release their spores.

With every appearance comes an opportunity for mushroom hunters to encounter new species. Up to 95% of the planet's fungal species have yet to be described, according to a 2023 report from the Royal Botanic Gardens, Kew. For several years, professional and amateur mycologists alike have been using DNA sequencing on foraged fungi, said Mandy Quark, a mycologist and head of communications at California. Survey of fungal diversity, which aims to add sequences from tens of thousands of fungi to scientific databases. Through sequencing, fungi enthusiasts often identify fungi that are the first examples of their kind in databases.

“Maybe we could go out now here in California — or really, wherever you are in North America — and we could easily find a new species of mushroom or fungi that hasn't been described yet,” Ms. Quark said.

At the Sonoma County Mycological Society's annual research camp last January, Ms. Quark and her partner Alan Rockefeller helped hundreds of campers identify fungi recovered from soil in the woods near Occidental, California. They feature mushrooms instead of corn dogs or French fries, piled high on picnic tables. In a makeshift laboratory, volunteers demonstrated how to extract DNA from tumors. Sequencing a short region of the genetic code of each fungus can distinguish them from one another.

Once collectors have a match for their sequence, they can enter the information on iNaturalist, a website where collectors can share their observations of the natural world. Meanwhile, organizations such as the Ohio Mushroom DNA Laboratory and the Mikuta Laboratory, founded by Stephen Russell, a biochemist at the University of Michigan, are entering sequences into scientific databases that are accessible to the research community. In this way, information generated by dispersed networks of foragers can be channeled directly to scientists and conservation organizations.

Ms Quark said recent years had brought about a breakthrough in sequencing. She said more than 21,000 samples have already been sequenced this year, up from 5,600 in 2022. “We will probably end the year with more than 40,000,” she added.

There are still many fungi that have not been identified. Some of these organisms, which live as a network of threads hidden in the soil, may not have sent up a fruiting body in years. But after heavy rains in Southern California, mushroom pickers may encounter mushrooms that haven't been seen in decades, Ms. Quark said.

Hence, generating sequences of fungi in soil may be the next step. Only then will it be possible to recognize the true diversity of North America's fungal species and, with climate change, consider ways to preserve what lies beneath the surface.

“We're at this amazing fulcrum now where we need to figure this out,” Ms. Quark said.