Russula sanguinea
Russula sanguinea, found in Tilden Park, late November. Edibility, not recommended.

Last month, after the first major storm of the season, I decided to risk the mud and go for a run on one of my favorite trails in Tilden Park. The trails, soft and spongy a week before, had turned into a gloppy, goopy mess, more suited to glissades than sprints. As I struggled to maintain momentum without falling, I couldn’t help but notice that the rains had brought more than mud.

All along the trail, mushrooms peeked out through the carpet of pine needles and sodden leaves. Before I knew it, Eric Burdon was singing in my head, “There was long ones, tall ones, short ones, brown ones, black ones, round ones, big ones….”

Some stood alone, as big as portabellas, others barely the size of a dime, huddled together in little bunches, still more clung to tree trunks and rotting logs. Mushroom season had sprung.

And I was singing along with Eric.

Not everyone shares my fascination with mushrooms, as famed fungi fanatic David Arora makes clear in his classic field guide, Mushrooms Demystified. Arora does his best to dispel what he sees as widespread “fungophobia” among Americans, a fear he calls irrational, given that only five or six of several thousand different wild North American mushroom species are deadly. Of course, the trick is knowing which ones.

Amanita ocreata
I found this specimen on a trail in Tilden Park and identified it, with the help of David Arora's Mushrooms Demystified, as Amanita ocreata, also known as destroying angel. If I'm right, I found one of the most poisonous mushrooms known.

Every year, hundreds of people get seriously ill from eating foraged wild mushrooms, prompting state Public Health Director Ron Chapman to issue an annual warning after winter’s first heavy rains to resist the urge to do so. Just last month, four people died at a home for the elderly in Placer County after their caregiver inadvertently served them what authorities believe were death caps.

Perhaps not surprisingly, most reports to the California Poison Control System involve children who sampled mushrooms that popped up in their lawn or neighborhood park. Since last January, 903 kids under six have required treatment for ingesting mushrooms.

Even experienced mushroom hunters can mistake poisonous and edible varieties, especially if they learned to forage in another country. Kent Olson, medical director of the CPCS, warns on the agency’s web site that many poisonous mushrooms in Northern California bear a striking similarity to edibles that grow in Europe and Asia, confusing even the most experienced mushroom foragers.

If you get the urge to test your mushroom hunting skills, do yourself a favor. Get a field guide like Arora’s and study it carefully to learn distinguishing characteristics of some of our resident species, both deadly and safe. And then sign up for a day hike or camping foray with the Mycological Society of San Francisco so you can forage with the experts.

But there’s far more to appreciate about mushrooms than their culinary appeal. Scientists are just beginning to get a handle on just how diverse the fungal kingdom really is.

For most of modern scientific history, fungi were misclassified as plants, based on their soil-bound, stationary existence. Had we just the naked eye to rely on, we might still restrict the world of fungi to the transient spore-filled fruiting bodies that burst through the soil long enough to reproduce. That would be like thinking the New York City subway system begins and ends with the above-ground stations scattered around the city streets.

But thanks to advances in microscopy and biochemical analysis techniques, scientists discovered that these “macrofungi” account for just a fraction of the diversity of species found in the fungal kingdom, which includes molds, yeast, lichens (a composite of fungi and algae) and parasitic rusts and smuts. (Corn smut, despite its unappetizing name, is in fact a tasty delicacy, better known by its Mexican name, huitlacoche.)

Even the reproductive structures we call mushrooms represent just the tip of the fungal iceberg, which consists of an intricate network of filaments (called mycelium) and lives as part of a thriving community of microbial and fungal species at different depths in the soil.

Amanita muscaria
Amanita muscaria, commonly known as fly agaric. I found this specimen under a fir in my front yard two years ago. Fly agaric has psychoactive properties and is considered poisonous.

Fungi play critical ecological roles as the primary decomposers in woodland and forest ecosystems and degrade everything from leaf litter to the notoriously indestructible lignin, which gives woody plants and trees strength and durability. Earlier this year, researchers discovered fungal species that can even break down polyurethane plastic.

Another type of fungus lives among the roots of plants and trees in a mutually beneficial symbiotic relationship. California’s iconic oaks depend on these mycorrhizal fungi to extend the reach of their roots to scavenge water and nutrients and to recycle nutrients from their own shed leaves. In exchange, fungi get carbohydrates from the trees.

In a 2001 paper describing the diverse functions of these symbiotic “ectomycorrhizal” partnerships, mycologist Anders Dalhberg ventured that perhaps 6,000 fungal species form these alliances with plants, allowing that the estimate must be conservative since some known species don’t produce fruiting bodies and it’s not clear how many remain unknown.

Though there is no such thing as a definitive field guide to mushrooms—there are simply too many mushroom species and too few mycologists to classify and identify them—Arora’s Mushrooms Demystified comes darn close. I’ve used it time and again to identify specimens throughout California, including a beautiful fly agaric in my own front yard.

On my run, I found what I thought was a Russula sanguinea, easy to recognize for its bright red cap and stem separated by white gills. I also saw what looked like a destroying angel, Amanita ocreata, on the trail. I brought them home, pulled out Arora’s guide and confirmed the Russula without a doubt. And I’m pretty sure I was right about the destroying angel.

I love exploring the woods to test my mushroom knowledge and look for new species I’ve yet to identify. But I’m still a dilettante. For now, I’m content to celebrate the ecological wonders and diversity of fungi with a long-haired leaping gnome in my head. And buy my wild mushrooms at the store.

Conquering Fungophobia 15 February,2013Liza Gross

  • debbie viess

    Hey Liza,
    Glad that you share a fascination with fungi, but it isn’t easy to do IDs when you are first starting out. The photo of a white mushroom that you show here is NOT an amanita at all, but an Agaricus, the same genus as our store bought white button mushrooms. Your mushroom lacks a volva, the universal veil that is characteristic of all amanitas.

    Which Agaricus you depict is a matter of conjecture, but about half of the species are toxic, the rest good to excellent edibles, but it is not easy to tell species in this group.

    BTW, mycological societies in California are popping up like, well, mushrooms! One based in the East Bay, where you did your collecting, is the Bay Area Mycological Society. We have been educating folks about fungi for almost nine years, and put on a FREE Fungus Fair at Pt. Reyes every January. This coming year it will be held the weekend of Jan. 3-4, 2015. David Rust and I are co-founders of this science-based society, and we were former members of the MSSF, who branched out to follow our own vision.

    We have been amused to hear that our former club the MSSF attempts to discredit what we do, by claiming that “we are not a non-profit!” This despite the fact, easily checked, that they themselves didn’t obtain non-profit status for their first 34 years of existence! Get back to us in 26 years, fellas!

    In fact, our field trips across CA and regular meetings at UC Berkeley and very popular (almost 900 members!) yahoogroups mushroom discussion forum, as well as that annual Fair, put on with the assistance of the Pt. Reyes National Seashore, are ALL free. So, we may not be a 501(3)(c) but we are in fact a non-profit. Or as I like to call us, a private philanthropic club.

    I would much rather be educating folks or walking in the woods than dealing with bureaucracies. Wouldn’t you?

    Here’s our website:

    See you in the woods!

    Debbie Viess
    Co-Founder, Bay Area Mycological Society


Liza Gross

Liza Gross, an award-winning independent journalist and senior editor at the biomedical journal PLOS Biology, writes mostly about conservation and public and environmental health. She was a 2013 recipient of the NYU Reporting Award, a 2013 Dennis Hunt Health Journalism fellow and a 2015 USC Data Journalism fellow.

Read her previous contributions to QUEST, a project dedicated to exploring the Science of Sustainability.

Sponsored by

Become a KQED sponsor