Foraging for mushrooms in monsoon season reveals a magic underworld
Story and photographs by Kimi Eisele
On a Sunday afternoon at the tail-end of what might be southern Arizona’s wettest monsoon season on record, I find myself on hands and knees on a steep slope of forest in the Catalina Mountains north of Tucson. I am peering at a shelf mushroom fanning its stripes out from the bark of a fallen tree.
It looks a like a seashell, dark brown with striations of white, gray, brown, and dark brown. Or maybe a little like the tail of a turkey.
“False turkey tail,” says Hernan Castro, the mycology enthusiast who is leading me and 13 others on an afternoon walk through the woods, expressly to look for mushrooms.
“Trichaptum biforme or violet-toothed polypore,” he says. A polypore is a shelf or bracket mushroom.

A few minutes later we come to a real turkey tail, which looks indeed similar to the false one. Castro points out the distinct bands in colors, the fuzz or velvety top, the tiny white pores underneath.
“Is it edible?” asks a nine-year-old boy named Max.
“Technically, yeah,” Castro says. “But it tastes like cardboard. You can make a tea out of it though.”
Later, I look up turkey tail, Trametes versicolor, and learn that it contains compounds that can reportedly boost the health of the human immune system. Some believe it can help fight cancer and improve gut bacteria.
Castro doesn’t harvest any of the turkey tail today. But his ethic is to leave at least one-third of what he finds in any given colony. “Some people will go out and take as much as they can. I really don’t like that. I teach people to be respectful toward nature.” To forage anything more than a small amount for personal use requires a permit from the US Forest Service, he adds.
Castro has been leading mushroom walks since 2018 to share his own passion and introduce others to the diversity of species in the region. Thousands of mushroom species can be found in the sky islands, an archipelago of mountain ranges that rises up from the Sonoran Desert. In dry years, many of these species may not make themselves known, but in a wet year, the mountains here hold what might be the greatest biodiversity of mushrooms in the country. “It’s all the microclimates,” Castro says. “Riparian areas to forests of oak, spruce, fir, and aspen trees.”

Indeed, the forest is as green and as wet as I’ve seen it. First-time creeks pour down slopes. Wispy grasses grow tall and green. Yellow columbine flowers dot the hill side beneath tall Douglas firs and ponderosa pines that reach high into the blue Arizona sky.
But the thing about foraging for mushrooms is that most of the time you’re looking down, scanning the bases of trees, looking under loose leaves, shifting around dirt. Unless you’re looking at shelf mushrooms, which can stack themselves up the side of a tree, sometimes so high you’d need an impossible ladder to harvest them.
Someone spots a shelf mushroom with circling stripes of brown, orange, and yellow. Dyer’s polypore, says Casiana Omick, who often joins Castro’s forays to help out when there are larger groups. “It can be used to dye wool and other animal hair,” she says, opening up David Aurora’s All That the Rain Promises and More: A Hip Pocket Guide to Western Mushrooms to show a picture a dog’s fur dyed yellow.
“I really wish I had blond hair,” Omick says, “so I could dye mine.”

Omick, who grew up in Tucson, says she became interested in mushrooms while living in Oregon over a year ago. When she moved back to Tucson recently, she read about how Mt. Lemmon and the Santa Catalinas have the highest biodiversity of mushrooms in the world during the monsoon season. At first she was daunted by the idea of identifying them. “But you start to learn things really quickly. I can go by myself now and am surprised by how much I do know.”
Fruiting bodies
There is more to mushrooms than meets the eye. The edible part—when it’s edible—is just a fraction of the actual fungal organism. What’s visible is the “fruiting body” of a mycelium, a network of fungal threads or hyphae growing underground or in decaying trees.
“These fruiting bodies sprouting up are not individuals, really, but part of that larger organism,” Omick says. “Which is such a good metaphor for life.”
Spotting such fruiting bodies is like finding treasure. They appear as bright white eggs. Or tiny skirts a-twirl. Or scalloped, multicolored fans. Or puffy marshmallows, sometimes as if they’ve been held over a flame and slightly charred.
Or as chopped-up gummy bears. “Are they edible?” Max asks, pointing to a cluster of tiny, flaming-orange-colored mushrooms.
“Yeah. But they don’t taste like much. Those are called witches’ butter,” Castro says.
When it comes to mushroom foraging, there are no easy rules of thumb to help a newbie—or even an experienced forager—determine what’s edible or not. You just have to know what you’re looking at. Castro recommends first foraging with someone knowledgeable and to use a guidebook and he never recommends that anyone ever try ingesting an unidentified mushroom.
“Usually you want to avoid amanitas,” he says. The genus has some 600 species, including some of the most toxic mushrooms. Eating them can cause severe illness or death.
Amanitas are often recognizable by their top bulbs, gills underneath, and a little “skirt” amidst the gills, he says.

We make our way up a steep slope, and Max finds a white mushroom the size of a softball with a hefty stem and a thick, wide, flat cap. “What is this?”
“That’s Boletus barrowsii, white king bolete,” Castro says, as the rest of us catch up. Max removes it from the ground, and Castro holds it up for everyone to look at.
“It’s got a robust, very thick stem. And when you look on the underside you can barely see pores. It has sponge texture, no gills. The pores are usually white or yellow.” Castro answers Max’s question before he has time to ask it. “That’s when you know it’s safe to eat. And it’s really good. It’s a rare find. Basically, the porcini, or our local version of the porcini.”
Once I hear that, I’m determined to find one.
“Look at the base of the maples,” Castro says. “They prefer the maples up here for some reason.”
Near the roots of a Douglas fir tree, Castro kneels to look at another shelf mushroom, this one shiny orange and white. “A reishi,” he says, cutting off thin slices, which he passes around for everyone to taste.
“This white part is edible raw. It’s really flavorful. Reishis are known as the queen of the medicinal mushrooms. They’ve been used for 10,000 years, according to the Chinese,” he says.

Finding the medicine
Castro became interested in the medicinal properties of mushrooms after his father suffered a series of strokes that left him with severe paralysis on one side of his body. After doctors said there wasn’t anything they could do to prevent further strokes or brain damage, Castro was motivated “to research anything and everything I could find on treatments to regenerate brain tissue damage, from stem cell therapy to herbalism,” he says.
He started reading studies from Japan on mushrooms and their potential to help nerve growth, brain tissue, and focus. In one study he read that Buddhist monks reported greater focus during meditation with the help of mushrooms. In other studies, he found reports of compounds in lion’s mane mushrooms helping to stimulate the growth of new nerve and brain tissue.
Though Castro had grown mushrooms before, he had never made an extract. “I was a little bit intimidated. This mushroom grew on a tree and I had never grown any that grew on trees before.”
But within a week, Castro says, it started growing. From there he harvested the fruit bodies, then dried and processed them into an extract. His father agreed to take the extract three times a day, consistently.
As a medical general practitioner, Castro’s father was not easily swayed by herbal—or fungal—medicine. “I would have to show him a lot of studies to try anything. So it surprised me that he followed through,” he says. “I’m glad he did.”

After six months, Castro’s father started gaining some mobility in his fingers. “I’d say, ‘Keep trying to move the rest of your hands.’ And eventually he did. His whole hand, then his arm, then sensation on his face and his legs came back. It took an entire year, but he had full regeneration,” Castro says.
The experience inspired Castro to continue researching the medicinal properties of mushrooms, and he began making extracts for family and friends. Then his grandmother offered to pay his way to the North American Mycology Association’s scientific foray in the White Mountains.
“It was the most magical thing that ever happened to me. I learned to identify so many mushrooms. I brought all these mushrooms back that I could use in my extracts, mushrooms I thought could only be found in Japan. But they’re here too.”
Eventually, Castro launched Desert Alchemist, a small company selling tinctures and extracts, which he says are the best way to benefit from medicinal compounds of mushrooms, as the cell walls of mushroom fruits can be difficult to digest.
While he has had success with mushrooms as medicine, the western medical establishment hasn’t quite caught up, he says. “There’s science that shows that mushrooms have these compounds in them and that the compounds do certain things, but it hasn’t been tested on humans in clinical trials. So, at this point, mushrooms are not supposed to prevent, cure, or treat any illnesses. Until further notice.”
Borderlands foraging
Castro was born in Nogales, Sonora, Mexico, where he lived until he was twelve before moving to Tucson. His mother is Apache, and part of his foraging, he says, is about connecting to his roots. “I did research on the Apache and knew that my ancestors traveled, nomads, migrated from Texas to Arizona and knew the sky islands like the back their hands. All the mountains. Now I’m trying to reconnect with lost knowledge.”
Most mushrooms found in Southern Arizona can be found elsewhere in the country, especially in the Rocky Mountains. But there are also new species being discovered in this region, Castro says.
A special borderlands mushroom is the Mexican matsutake. “It smells like cinnamon. Typically, matsutakes smell like dirty socks. This one tastes really good. It did give me a mild stomachache. But I’ll keep eating it,” Castro says.
He returns to Nogales often to forage with his six-year-old nephew. “He wants to learn everything. He knows more scientific names than most people. He’s going to be a prodigy,” Castro says.
Castro says he’s also interested in contributing more to mycology and mushroom foraging in the borderlands. “There’s a lot of hunger for knowledge in Mexico.” Castro hopes to feed that through his TikTok, Instagram, and YouTube accounts, as well as future TedTalks and excursions there. “As long as someone else helps set up the locations, since a lot of the prime locations there are considered ‘narco-territory.’ It can be dangerous.”

We climb back down the slope to the trail, where Omick finds a russula, a mushroom with a reddish cap about size of a small corn tortilla.
“These come in very colorful tops,” Castro says. “Grays, greens, yellows, pinks, reds, purples. I would say they’re edible, but some people get sick. Gastrointestinal distress. They’re popular in Poland and Russia.”
One of the women in the group, originally from Russia, confirms this. “In Russia, we brine them into pickles,” she says. “We rarely fry mushrooms with gills.”
Castro tells us to keep scanning the young maples on either side of the trail for white king boletes. Every promising white mound I find turns out to be a rock.
I hear Max’s voice up ahead asking about another mushroom. “Is it edible?”
But scanning the forest floor, I realize that every mushroom—maybe every rock, tree, flower, too?—is worthy of my attention, regardless of whether or not it’s edible. Some of the most toxic mushrooms are also the most beautiful. Foraging for fruiting bodies simply offers good sensory nourishment: fuzzy caterpillars, trilling thrushes, bright green mosses growing up the sides of trees delight along the way.

Late in the afternoon, Castro pulls up another big bolete, not white but orangey-red. He slices it down the middle to show how it bleeds blue. When he holds it up, the whole thing appears like a rainbow in his hands.
“Is it edible?” Max asks.
“I wouldn’t,” Castro says.
At the end of the walk, Castro divvies up the white king boletes in his basket, making sure everyone gets one. Somehow, I end up with a giant one, the size of a curled-up kitten, and I don’t complain. When I get home, I slice it up and sauté it in butter, garlic, and thyme—a tasty gift from the underworld.
Resources
Desert Alchemist products can be found online here or on Etsy and at the Heirloom Farmer’s Market at Rillito Park in Tucson.
Castro leads regular mushroom forays and workshops in the summer and fall. Learn more here.
David Aurora’s All That the Rain Promises and More: A Hip Pocket Guide to Western Mushrooms is a go-to guide for identifying mushrooms of the region.
Fascinating. I had no idea about the abundant diversity of mushroom in our region.
Beautiful job on the article and photos.