The call arrived at 7 p.m. from a hospital in Davis County, Utah. A worried emergency room doctor wanted University of Utah mycologist Bryn Dentinger (Ph.D. ’07) to identify a mushroom possibly eaten by a boy who was a patient.

Called a Lepiota, the mushroom was one of a genus that includes several lethal species. Try as he might, Dentinger couldn’t positively ID it from the cellphone photo sent by the hospital, so the boy’s father drove 30 miles to Salt Lake City, bringing the mushroom to Dentinger’s lab.

Dentinger examined the Lepiota under a microscope and generated a DNA barcode, determining that it was poisonous. Meanwhile, he advised the ER to monitor the boy for liver failure.

The child survived and is fine. “It was a very good outcome,” says Dentinger, pointing out that the boy likely handled the mushroom but didn’t eat it. Had he consumed it, he almost certainly would have experienced liver failure, and he may have died.

Identifying fungi for the ER is only one part of Dentinger’s work. He also hunts for new species and determines their origins.

Though the Lepiota is a known variety, it has been found only twice in the local area. Likely, its arrival in arid Davis County was due to a seemingly unrelated phenomenon: the transporting of sod for agricultural and landscaping purposes. According to Dentinger, foreign species hitchhike around the nation in these carpets of grass.

Fungi are one of the least-known groups of eukaryotes (multicelled organisms), says Dentinger, an associate professor of biology at the U of U and curator of mycology at the Natural History Museum of Utah. Therefore, it’s important to increase taxonomy, or the classification and naming of different species. Fungi may just be the stuff of life: They have symbiotic relationships with 90 percent of the plants on Earth and are thought to have fostered the colonization of land 450 million years ago. They are at the base of most food chains.

Cataloging them is tough work for mycologists. Fungi are ephemeral, and stubbornly evade attempts to culture them in captivity. They are largely undocumented in much of the world, particularly in South America and Africa. Dentinger, who started as a teenage mushroom hunter in northern Minnesota—he was born in Duluth—now works with other scientists to establish baselines of knowledge in Cameroon and Guyana. They recently identified four new mushrooms, two in each country. They hope to determine whether there are fungi links between South America and Africa, which would indicate that mushrooms formed when both were part of the prehistoric land mass Gondwana.

Dentinger began his formal training in mycology at the University of Minnesota, where he says he was fortunate to work under renowned expert David McLaughlin, now a professor emeritus in the College of Biological Sciences. “The University has one of the best mycology resources available,” Dentinger says, noting that strong programs in plant pathology and plant biology provide unusual breadth in a study area that is mysterious to the average person. Mycology is a small world, which means he still routinely interacts with U researchers and has even provided mushroom samples for U studies.

For Dentinger, identifying harmful invasives and finding new fungi that help piece together our global history is all part of mycology’s appeal. “If you talk with anyone who studies fungi, there’s a real fascination with the treasure hunt,” he says. “Ever since I started hunting chanterelles in the North Woods as a kid, I’ve never known what I’d find.”